Device for vehicle tyres having inflation valve and electronic pressure monitoring module

Abstract

A device for a motor vehicle tyre, comprising an inflation valve comprising an elastomeric body (2) having an inner shoulder (6) supported in the tyre on a rim edge, and comprising an electronic module of a system for monitoring the inside pressure of the tyre, the electronic module is arranged in a housing (12) made of two half-shells assembled along a parting line, the valve comprising an elastic ring (14) connected to an inner shoulder (6) of the body in which the housing (12) of the electronic module is received to retain the housing, the elastic ring surrounding the parting line between the half-shells of the housing.

Description

[Technical field]

[0001] The invention relates to a device for a motor vehicle tyre, comprising an electronic module of a system for monitoring tyre pressure and an inflation valve, and to a wheel equipped with such a device, and to a method for assembling a wheel of this type. [Background Technology]

[0002] A known type of tire pressure monitoring system (TPMS), disclosed in particular by document FR-A1-3084288, comprises a valve made of elastomer comprising a rigid upstream tube equipped with a non-return valve to enable inflation and a rigid downstream tube extending the upstream tube, with a seal between the two tubes.

[0003] In this document Figure 5 In the configuration shown, the electronic module of the system for monitoring tire pressure, which includes a pressure sensor, a power supply battery and an electronic circuit including a radio transmitter, is fastened to the end of the downstream tube entering the rim using a screw screwed into a tapered pipe thread formed in the axial hole of the tube. Thus, the downstream tube of the valve serves to form an attachment point for the electronic housing inside the tire, which eliminates the need to provide a separate system for fastening the housing directly to the rim.

[0004] In addition, the housing of the electronic pressure monitoring module located inside the tire must be highly fluid-tight to protect the internal components from contamination from the inside of the tire, such as moisture carried in the condensed inflation air, dust present during the tire installation process, or grease used to facilitate tire installation so that the tire belt layer slides on the rim edge, all of which may be corrosive.

[0005] Furthermore, since European regulations require tire pressure monitoring systems to be installed on all four wheels of motor vehicles, low-cost modules are needed to limit the impact on the total vehicle price.

[0006] To manufacture these electronic module housings, it is known to manufacture two half-shells to house the components and then assemble them using industrial mechanical systems to ensure the seal between the two parts. In particular, a peripheral gasket can be provided between the half-shell and the assembled component, the assembled component being pressed against this gasket with screws or rivets. The housing can also be sealed, for example by gluing or welding the half-shells, which guarantees mechanical strength and fluid tightness.

[0007] However, these housing sealing systems are expensive, requiring, inter alia, attached assembly components, or implementation of sealing methods, which incur assembly and supply costs.

[0008] Furthermore, these electronic modules are difficult or impossible to repair due to the difficulty in opening and closing the housing while ensuring fluid tightness, while they contain parts that may be exhausted (such as power supply batteries that must be replaced after a certain period of use) or parts that are easy to repair. This makes the electronic modules consumables that have limited repair options and must be thrown away in the event of minimal wear or failure, which creates cost and environmental issues related to the manufacture of new housings and the mandatory reprocessing of old housings. In particular, the batteries are usually lithium batteries that require special recycling, which is very costly.

[0009] The present invention is particularly intended to overcome these problems in the prior art. [Summary of the invention]

[0010] For this purpose, a device for motor vehicle tires is proposed, comprising an inflation valve including an elastomeric body having an internal shoulder supported in the tire on the edge of the rim, and the device including an electronic module of a system for monitoring the inside pressure of the tire, the electronic module being arranged in a housing made of two half-shells assembled along a parting line, the device being noteworthy in that the valve includes an elastic ring connected to the internal shoulder of the body, in which the housing of the electronic module is received to retain the housing, the elastic ring surrounding the parting line between the half-shells of the housing.

[0011] An advantage of this device is that the elastomer of the body (a material that is cheap to mold due to its elasticity) performs the function of retaining the housing of the electronic module inside the tire and also forms a protective contour around the parting line between the two half-shells of this housing.

[0012] This provides a simple housing that is cheap to manufacture, for example the half shells can be quickly snapped together and then easily opened for maintenance, repair or recycling. When the module is subsequently put back into service, positioning and tightening the housing in the ring of the valve automatically ensures that the housing is retained and protected as originally installed.

[0013] The device for a tyre according to the invention may further comprise one or more of the following features, which may be combined with each other.

[0014] Advantageously, the elastic ring forms a seal around the half-shells, protecting the parting line.

[0015] Advantageously, the housing comprises an outer groove surrounding the parting line of the housing, receiving the elastic ring.

[0016] In this case, the outer groove advantageously has a hollow circular arc cross section.

[0017] According to one embodiment, the elastic ring has a cross section forming a circle fitting into the groove.

[0018] According to another embodiment, the elastic ring has a cross section comprising an arcuate portion fitting into the outer groove, extended on each side by a lip covering the edge of the housing beyond the outer groove of the housing.

[0019] Advantageously, the housing comprises a hole which receives the end of the rigid tube of the valve protruding into the elastic ring.

[0020] Advantageously, the two half-shells of the housing are assembled together with an unsealed joint.

[0021] Advantageously, the elastic ring is formed with the elastomeric valve body by means of the same mould.

[0022] The present invention also relates to a motor vehicle wheel, which includes a tire mounted on a rim and equipped with an inflation valve. It is worth noting that the motor vehicle wheel includes a device for the tire, which includes any one of the above-mentioned features, and the electronic module housing of the device is fastened in the elastic ring of the valve.

[0023] The invention also relates to a method for assembling a wheel comprising the above-mentioned features, notably comprising: a step of inserting the valve body into a hole in the rim before mounting the tire on the rim, and a step of fastening the housing of the electronic module in the elastic ring of the valve body. [Drawings]

[0024] The invention may be better understood, and further features and advantages will become more apparent, from the following description given by way of example and with reference to the accompanying drawings, in which:

[0025] [ Figure 1 ] Figure 1 A device for a tire according to the invention is shown,

[0026] [ Figure 2 ] Figure 2 is an exploded view of the device.

[0027] [ Figure 3 ] Figure 3 is a schematic diagram of a cross section of the device through the electronic module,

[0028] [ Figure 4 ] Figure 4 shows a device according to a variant,

[0029] [ Figure 5 ] Figure 5 The device is shown with a portion of the elastic ring cut away,

[0030] [ Figure 6 ] Figure 6 is a schematic diagram of a section of the device through the electronic module. [Specific implementation method]

[0031] Figure 1 , Figure 2 and Figure 3 A valve is shown having an elastomeric body 2 arranged along a main axis A, the valve comprising, from one side EXT outside the wheel, an elongated portion comprising a rigid axial duct 8 receiving the inflation pressure from the tyre, an annular groove 4 arranged to fit into a hole in the metal plate of the rim, the shoulder bearing against the inside of the metal plate. The rigid duct 8 extends from an inner end 10 extending beyond the shoulder 6 to supply air to the tyre.

[0032] The closed elastic ring 14, made in the same mould as the elastomer of the body 2, has a circular profile arranged in the axial plane of the valve. The elastic ring 14 has a constant arcuate section into which the inner end 10 of the rigid conduit 8 opens.

[0033] The electronic module of the system for monitoring tire pressure comprises a housing 12, which comprises a lower half shell 20 and an upper half shell 22 made using a plastic mold, which after assembly form a thin housing of substantially square shape. The housing 12 houses an electronic circuit board 24 wedged into the housing, which supports welded components including a pressure sensor, a radio transmitter and a lithium battery 26 welded under the board.

[0034] The half shells 20, 22 of the housing 12 are assembled to each other along a flat parting line arranged in the thickness of the housing, the relative positioning of these half shells being ensured by internal lugs 28. The closed housing 12 has an outer groove 30 around its contour with a constant hollow section forming a semicircle centered on the parting line.

[0035] exist Figure 1 In the assembled state shown, the housing 12 is inserted into the elastic ring 14 by stretching and deforming the ring to fit into the outer groove 30 of matching shape, so that half of the cross section of the ring enters the groove. The hollow section of the groove that receives the elastic ring 14 compressed in the groove 30 holds the housing 12.

[0036] Stretching the elastomeric ring 14 around the housing 12 creates sufficient compression on the surfaces of the two parts of the groove 30 formed by the two half-shells 20, 22 to seal the two parts and protect the parting line.

[0037] The upper half shell 22 comprises a hole 32 on one side which opens on the other side without entering the inside of the housing, the hole being designed to receive in a fitting manner the end 10 of the rigid conduit 8 of the valve so as to position the housing on the valve and to provide additional retention in addition to that provided by the elastic ring 14.

[0038] Inserting the end 10 of the rigid conduit 8 into the hole 32 of the previously assembled shell 12 and then fitting the shell in the ring by stretching the elastic ring 14 allows a simple and rapid assembly that does not require additional fastening parts and that simultaneously holds the shell in the tire and provides a seal between the two half-shells 20, 22 of the shell.

[0039] Furthermore, by removing the housing 12 from the elastic ring 14 by deforming it, the electronic module can be simply removed without the need for tools for maintenance or repair. The housing 12, which is closed without gluing or welding, can then be opened quickly and cleanly (for example by removing the closing clips), making it possible to carry out work in the housing, after which the housing can be closed by performing these operations in reverse. The half-shells 20, 22 are then resealed with the same quality as the original by reassembling the housing 12 in the elastic ring 14 of the valve fastened to the rim.

[0040] Figure 4 , Figure 5 and Figure 6 A variant of an elastomeric valve body is shown, comprising an elastic ring 14 of constant section inside the tire, with an arcuate portion in the form of an arc 42 directed towards the inside of the ring fitted into the outer groove 30 of the housing 12, and a lip 44 on each side, the lip covering the top or bottom arcuate edge of the housing. In this configuration, the hole 32 and the end 10 of the rigid conduit 8 of the valve can be omitted, the housing then being positioned and held on the valve only by the elastic ring 14.

[0041] The outer end of the valve is shown with a protective cap 40 which closes its inflation orifice.

[0042] The inner arcuate portion of the cross section of the elastic ring 14 bears similarly and simultaneously on the two half-shells 20 , 22 , and the lips on each side bear against and cover the arcuate edges of these half-shells to ensure greater fluid tightness.

[0043] The elastomer thus protects the profile of the casing 12 from potential impacts, in particular during the mounting of the tyre.

Claims

1. A device for a motor vehicle tire, comprising an inflation valve, the inflation valve comprising an elastomeric body (2) having an inner shoulder (6) supported in the tire on the edge of the rim, and the device comprising an electronic module of a system for monitoring the inner pressure of the tire, the electronic module being arranged in a housing (12) made of two half-shells (20, 22) assembled along a parting line, wherein The valve comprises an elastic ring (14) connected to an inner shoulder (6) of the body, in which the housing (12) of the electronic module is received to retain the housing, the elastic ring surrounding the parting line between the half shells (20, 22) of the housing.

2. The device for a tire according to claim 1, wherein: The elastic ring (14) forms a seal around the half shells (20, 22), protecting the parting line.

3. The device for a tire according to claim 2, wherein: The housing (12) includes an outer groove (30) surrounding a parting line of the housing and receiving the elastic ring (14).

4. The device for a tire according to claim 3, wherein: The outer groove (30) has a hollow arc cross section.

5. The device for a tire according to claim 3 or 4, wherein: The elastic ring (14) has a cross-section formed into a circle that fits into the groove (30).

6. The device for a tire according to claim 3 or 4, wherein: The elastic ring (14) has a cross-section comprising an arcuate portion which fits into the outer groove (30), extended on each side by a lip (44) which covers the edge of the housing (12) beyond the outer groove (30) of the housing.

7. A device for a tyre as claimed in any one of the preceding claims, wherein: The housing (12) includes a hole (32) which receives the end (10) of the rigid tube (8) of the valve protruding into the elastic ring (14).

8. A device for a tyre as claimed in any one of the preceding claims, wherein: The two half shells (20, 22) of the housing are assembled together with an unsealed joint.

9. A device for a tyre as claimed in any one of the preceding claims, wherein: The elastic ring (14) and the elastomeric valve body (2) are formed by the same mold.

10. A wheel of a motor vehicle, comprising: A tyre mounted on a rim and equipped with an inflation valve, wherein the motor vehicle wheel comprises a device for a tyre as claimed in any one of the preceding claims, comprising its electronic module housing (12) fastened in an elastic ring (14) of the valve.

11. A method for assembling a wheel as claimed in claim 10, the method comprising: Before mounting the tire on the rim, the valve body (2) is inserted into the hole in the rim, and the housing (12) of the electronic module is fastened in the elastic ring (14) of the valve body.

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