Automotive wheel measurement sensor

Abstract

A measuring sensor (1) for a motor vehicle wheel, said sensor (1) comprising a measuring module configured to measure at least the pressure inside said wheel and an inflation valve (10), and a housing (20) in which said measuring module is mounted, comprising a locking wall (241), an orifice (242), and at least one stop element (25), the valve (10) comprising a retaining head (124) having an oblong shape with dimensions smaller than those of the locking orifice (242) and comprising at one end a first locking portion (124A) and at the other end a second locking portion (124B), the first locking portion (124A) being locked between the locking wall (241) and at least one stop element (25), and the second locking portion (124B) bearing against the locking wall (241). Figure for the abbreviation: Figure 1

Description

Title of the invention: Measuring sensor for a motor vehicle wheel Technical field

[0001] The invention relates to the field of sensors for motor vehicle wheels and more particularly concerns a measurement sensor comprising a measurement module embedded in a housing secured to an inflation valve. Prior art

[0002] In a motor vehicle, it is known to use sensors to monitor tire pressure. Such a sensor can be mounted in each of the vehicle's wheels and is dedicated to measuring parameters such as pressure and temperature. This type of sensor is known as a "TPMS" sensor ("Tire Pressure Monitoring System").

[0003] As is known, a TPMS sensor comprises a housing in which a measuring module is mounted to measure at least the tire pressure and sometimes also the temperature or acceleration. There are two common solutions for mounting the sensor in the wheel. As is known, the measuring module sends the measurements taken to an electronic control unit of the vehicle.

[0004] In a first solution, the casing is glued inside the tire but such a solution has significant drawbacks, in particular that of coming loose at high rotation speed of the wheel or after a long period of use.

[0005] In a second solution, the housing is attached to the wheel inflation valve.

[0006] A known type of valve, called "snap-in", comprises a one-piece valve body and a hollow rigid tube. The valve body comprises a hollow trunk of circular section and a stop comprising a neck in the form of an annular groove for blocking the valve body in an orifice of circular section of the rim. The hollow rigid tube comprises an internal portion extending into said valve body and an external portion extending in the extension of the stop of the valve body to a free end.

[0007] A first technique for mounting the housing on the valve consists of fixing it, for example by screwing, on the free end of the hollow rigid tube. This technique has the advantage of providing a robust assembly, but it requires, on the other hand, providing a space of several millimeters between the housing and the inflation valve in order to allow for deformations of the latter when mounting the sensor on the rim. However, such a distance can increase the imbalance phenomenon linked to the mass of the rotating sensor, which leads to a significant reduction in the performance of the sensor.

[0008] A second technique consists of providing the housing with an assembly sleeve capable of sliding along the hollow rigid tube of the valve and of equipping each sensor with means for securing the housing to the valve so that the housing is in direct extension of the valve and the housing and the valve are both pressed against the rim. The means for securing the inflation valve and the housing are, for example, of the clip type, elastic ring, spring ring of the “lyre” type, “0-clamp” crimping collar, screw collar, locking plate, etc.

[0009] This technique makes it possible to increase the performance of the sensor because the housing is pressed against the rim. On the other hand, the securing means are likely, with a significant probability, to be damaged or even unlocked, during the fitting and removal of the tire or during the rotation of the wheel. In addition, a majority of these securing means require specific tools for their installation and removal, which can complicate the steps of fitting and removing the sensor.

[0010] There is therefore a need for a solution to at least partially remedy these drawbacks. Statement of the invention

[0011] To this end, the invention firstly relates to a measurement sensor for a motor vehicle wheel, said measurement sensor comprising a measurement module, configured to measure at least the pressure inside the wheel, and: - an inflation valve adapted to be mounted on the rim of the wheel and comprising a one-piece valve body comprising a hollow trunk of circular section, a cone and a neck in the form of an annular groove for locking the valve body in an orifice of circular section of the rim, and a hollow rigid tube comprising an internal portion extending into said valve body and an external portion extending in the extension of the cone of the valve body to an end comprising a fixing head, - a housing in which the measuring module is mounted, said housing comprising on its upper wall a fixing member which comprises a blocking wall provided with an orifice, crossed by a part of the external portion of the hollow tube and having an oblong shape, and at least one stop element, spaced from the blocking wall, the fixing head having an oblong shape of dimensions smaller than those of the blocking orifice and comprises at one end a first blocking portion and at a second end a second blocking portion, the first blocking portion being blocked between the blocking wall and the at least one stop element and the second blocking portion bearing against the blocking wall.

[0012] The oblong shape, i.e. longer than wide, of the fixing head makes it possible to secure the valve and the housing together. The securing is carried out by pushing the fixing head into the orifice, then rotating the valve on its longitudinal axis. The first locking portion and the second locking portion of the fixing head, initially oriented in the same direction as the orifice, are then in contact with the fixing wall, which in particular makes it possible to lock the inflation valve in translation relative to the housing. The first fixing portion is also in contact with the stop element. This stop element also serves to lock the inflation valve in translation relative to the housing. The first fixing portion is also in contact with both the locking wall and the stop element, and the resulting friction makes it possible to lock the inflation valve in rotation relative to the housing.

[0013] Preferably, the measurement sensor has a fixing head which extends orthogonally to the longitudinal axis of the external portion, the width of the fixing head being equal to the diameter of the external portion and the length of the fixing head being less than or equal to the diameter of the orifice of the fixing member of the housing. As a result, the surface area of ​​the first locking portion and the second locking portion in contact with the locking wall is larger. The surface area of ​​the first locking portion in contact with the stop element is also larger. The rotational locking of the inflation valve in rotation relative to the housing is thus improved.

[0014] More preferably, the external portion of the hollow rigid tube comprises, at its junction with the fixing head, an annular fixing groove configured to receive a portion of the locking wall. Thus, after rotation, the locking wall is on one side in contact with the external portion of the hollow tube, and on the other in contact with the first and second locking portions of the fixing head. The resulting friction is greater, which improves the rotational locking of the inflation valve relative to the housing.

[0015] Advantageously, in the presence of this annular groove, the dimensions of the fixing head are less than or equal to the diameter of the external portion of the hollow tube. The fixing head is thus more compact and the annular groove allows translational locking of the valve relative to the improved housing.

[0016] Advantageously, the housing comprises a tubular member extending perpendicularly from the blocking wall towards the valve body in the extension of the orifice of said blocking wall, the dimensions of the tubular member being substantially greater than the diameter of the external portion of the hollow tube in order to allow the tubular member to fit onto the external portion of the hollow tube. Thus, once engaged and rotated in the orifice, the friction between the thus engaged section of the external portion of the hollow tube and the tubular member improves the blocking of the inflation valve relative to the housing.

[0017] In one embodiment, the measurement sensor comprises on the fixing head at least one relief shape extending projecting from the first locking portion and / or from the second locking portion, preferably from the first locking portion and from the second locking portion. The relief shape(s) thus allow frictional locking between the locking wall and the at least one stop element at the first locking wall and frictional locking against the locking wall at the second locking wall, which improves the rotational locking of the inflation valve relative to the housing.

[0018] For example, the raised shape(s) may be of the rib, rim, protrusion or boss type.

[0019] In one embodiment, the housing comprises at least one reinforcement supporting the at least one stop element. The reinforcement supporting the at least one stop element thus makes it possible to prevent its deformation during frictional locking of the first locking portion of the fixing head between said at least one stop element and the locking wall. The reinforcement makes it possible to reinforce the mounting of the housing and the valve body for repeated assemblies and disassemblies. Advantageously, at least one reinforcement is aligned with the axis of the valve body and extends by a vertical ridge in contact with part or all of the fixing head. Thus, the forces exerted on the valve are more balanced at the level of the housing, which reduces the risk of deformation of the fixing member.The ridge helps to localize the friction between the fixing head and the stop element, and thus avoids the entire surface of the fixing head being pressed against the stop element when rotating the valve in the housing.

[0020] Preferably, the housing comprises at least one protrusion extending projecting from the upper wall of the housing between the locking wall and the at least one stop element. The projecting protrusion thus creates an additional friction point on the first locking portion after rotation of the valve body, which improves the rotational locking of the inflation valve relative to the housing.

[0021] More preferably, the measuring sensor comprises at least one notch formed in at least one of the first locking portion or the second locking portion. Thus, after rotation, the protrusion projecting from the upper surface of the housing is housed in the notch of the first locking portion to lock the fixing head in rotation.

[0022] The invention also relates to a vehicle wheel, comprising a rim and a tire, equipped with at least one measuring sensor according to the invention.

[0023] The invention also relates to a motor vehicle, comprising at least one wheel, said wheel comprising a rim and a tire and being equipped with at least one measuring sensor according to the invention.

[0024] The invention also relates to a method for assembling a measurement sensor according to the invention comprising a step of relative positioning of the valve body with respect to the housing, a step of inserting the fixing head into the orifice of the locking wall of the housing, and a step of rotating the fixing head along the longitudinal axis in order to lock the first locking portion between the locking wall and the at least one stop element and the second locking portion against the locking wall. Preferably, during the rotation step, the fixing head is turned a quarter turn. Brief description of the drawings

[0025] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which: [Fig.l] [Fig.l] schematically illustrates an embodiment of a measuring sensor according to the invention, comprising a valve and a housing for the measuring element assembled together. [Fig.2] [Fig.2] schematically illustrates a first embodiment of the valve of the measuring sensor according to the invention. [Fig.3] [Fig.3] schematically illustrates a second embodiment of the valve of the measuring sensor according to the invention. [Fig.4] [Fig.4] schematically illustrates a front view of a first embodiment of the housing for the measuring element of the measuring sensor according to the invention. [Fig.5] [Fig.5] schematically illustrates a top view of the same embodiment of the housing for the measuring element of the measuring sensor according to the invention as in [Fig.4]. [Fig.6] [Fig.6] schematically illustrates a variant of the embodiment of the housing for the measuring element of the measuring sensor according to the invention presented in Figures 4 and 5. [Fig.7] [Fig.7] schematically illustrates a view of the relative positioning of the housing and the first embodiment of the measuring sensor valve for the assembly of the measuring sensor according to the invention. [Fig.8] [Fig.8] shows the assembly process of the measuring sensor from the valve and the housing. Description of the embodiments

[0026] [Fig.l] represents an example of a measuring sensor 1 according to the invention.

[0027] The sensor 1 comprises a valve 10 and a housing 20.

[0028] The valve 10 comprises a valve body 110 and a hollow rigid tube 120.

[0029] The valve body 110 is in one piece and comprises a hollow trunk 112 of section circular, a cone 114 formed at a first end of the hollow trunk 112, a neck 116 which separates the base of the cone 114, a stop 117 and a cap 118 mounted on the second end of the hollow trunk 112, opposite the first end.

[0030] The cone 114 is made of a slightly flexible material and allows the valve body 110 to be guided into a circular section orifice of the rim (not shown) of the tire. The base of the cone 114 can thus deform when the valve 10 is inserted into the rim and cover the perimeter of the orifice of the rim once the latter has reached the neck 116.

[0031] The neck 116 allows the rim of the tire to be inserted into the valve body 110 and thus secure the valve 10 with the rim. Due to the presence on either side of the neck 116 of the base of the deformable cone 114 and the stop 117, the contact between the rim and the valve 10 is sealed and ensures that there is no air leakage from the tire in this area.

[0032] The stop 117 makes it possible to block the valve body 110 in translation when the valve 10 is inserted into the rim of the tire.

[0033] The cap 118 protects the threaded connection of the valve body 110 allowing the inflation of the tire (not shown).

[0034] The hollow rigid tube 120 comprises an internal portion (not shown) inside the valve body 110 and an external portion 122 extending in the extension of the stop 117 of the valve body 110 to an end comprising a fixing head 124. The external portion 122 also comprises an inflation orifice 121.

[0035] The inflation orifice 121 allows the passage of the pressurized air flow having passed through the tube 120 during the tire inflation operation. In [Fig.l], the inflation orifice 121 is shown on the fixing head 124, but alternatively the inflation orifice 121 could be present on the wall of the external portion 122.

[0036] As shown in [Fig. 2], the fixing head 124 is oblong in shape and extends in a plane orthogonal to the longitudinal axis X of the external portion 122, defining a first locking portion 124A and a second locking portion 124B, which are identical. An annular fixing groove 126 is hollowed out on the external portion 122 at the interface of the fixing head 124 in order to improve the frictional locking of the fixing head 124 relative to the housing 20, as will be described below.

[0037] The first fixing portion 124A and the second fixing portion 124B each comprise in this example a notch 128 formed at their free distal end.

[0038] In another embodiment shown in [Fig. 3], the fixing head 124 further comprises two relief shapes 129 which each extend projecting from the first fixing portion 124A and from the second fixing portion 124B.

[0039] The housing 20 shown in Figures 3 and 4 comprises an upper wall 21, a lower wall 22, a side wall 23, a fixing member 24 and a stop element 25.

[0040] The fixing member 24 comprises a locking wall 241 extending orthogonally from the upper wall 21 of the housing 20 and delimiting an oblong orifice 242.

[0041] A tubular member 243 extends orthogonally from the blocking wall 241, extending the orifice 242.

[0042] The locking wall 241 comprises two locking elements 244, each in the form of an offset of material extending into the orifice 242 and making it possible to prevent the removal of the fixing head 124 once it is resting on said locking elements 244, as will be described below.

[0043] A protrusion 245 projects from the upper wall 21 between the locking wall 241 and the stop element 25.

[0044] The housing 20 shown in [Fig.5] alternatively comprises a reinforcement 26 and a reinforcement 27.

[0045] The reinforcement 26 has a triangular shape and extends over the upper wall 21 so as to support the fixing member 24.

[0046] The reinforcement 27 also has a triangular shape and extends over the upper wall 21 so as to support the stop element 25.

[0047] The reinforcement 27 extends on the other side of the stop element 25 by a vertical ridge 271 whose height is equal to the length of the fixing head 124.

[0048] All the elements of the single-piece housing 20 described above are made from the same material, preferably by molding a plastic material.

[0049] The attachment of the valve 10 to the housing 20 for the assembly of the measuring sensor 1 is shown in [Fig.7]. For the sake of clarity, the wheel and more particularly the rim have not been shown.

[0050] In a first step E1, the valve body 110 is inserted into the rim fixing orifice and is positioned opposite the orifice 242 defined in the blocking wall 241 of the housing 20. The valve body 110 is rotated on its longitudinal axis X so that the fixing head 124 is oriented in the same direction as the oblong orifice 242 defined by the tubular member 243.

[0051] In a second step E2, the valve body 110 is advanced towards the housing 20 so that the fixing head 124 and a part of the external portion 122 penetrate into the orifice 242 of the blocking wall 241 of the housing 20. The insertion stops when the fixing head 124 comes into abutment against the stop element 25. At this stage, the tubular member 243 is fitted onto the end of the external portion 122 of the hollow tube of the valve 10.

[0052] In a third step E3, the valve body 110 is rotated a quarter turn about its longitudinal axis X. The rotation brings the first locking portion 124A of the fixing head 124 into contact with the upper wall 21 of the housing 20. With respect to the longitudinal axis X, the first locking portion 124A is on one side in contact with a locking element 244 of the locking wall 241 and on the other side in contact with the stop element 25. The rotation brings the second locking portion 124B of the fixing head 124 into contact with a locking element 244 of the locking wall 241.

[0053] The contact between the first locking portion 124A on the one hand, a locking element 244 and the stop element 25 on the other hand, as well as the contact between the second locking portion 124B and the other locking element 244 ensure the locking in translation of the valve body 110.

[0054] During rotation, the two locking elements 244 are inserted into the annular fixing groove 126 and are clamped between the external portion 122 of the valve body 110 and the two locking portions 124A and 124B. The resulting friction ensures that the valve body 110 is locked in rotation.

[0055] In the embodiment shown in [Fig.7], the edge of the first locking portion 124A rubs against the upper wall 21 and the protrusion 245 is inserted into the notch 128. The friction and locking effect at the notch 128 ensures that the valve body 110 is locked in rotation.

[0056] In the embodiment of the valve body 110 shown in [Fig. 3], the two raised shapes 129 are in abutment against the ridge 271 which extends the reinforcement 27 through the stop element 25 following the insertion of the external portion 122 of the valve body 110 into the fixing member 24. At the end of the rotation of the valve body 110, the first locking portion 124A and the second locking portion 124B are therefore in friction on one side against the locking wall 241 and on the other against the ridge 271 by these raised shapes 129. The friction effect of these raised shapes 129 makes it possible to ensure the rotational locking of the valve body 110, while preventing the friction on the stop element 25 from hindering the rotation for fixing the valve 10 on the housing 20.

Claims

Claims

1. Measuring sensor (1) for a motor vehicle wheel, said measuring sensor (1) comprising a measuring module, configured to measure at least the pressure inside said wheel, and: - an inflation valve (10) adapted to be mounted on the rim of the wheel, said valve (10) comprising: • a single-piece valve body (110) comprising a hollow trunk (112) of circular section, a cone (114) and a neck (116) in the form of an annular groove for locking the valve body (110) in an orifice of circular section in the rim, • a hollow rigid tube (120) comprising an internal portion extending into said valve body (110) and an external portion (122) extending in the extension of the cone (114) of the valve body (110) to an end comprising a fixing head (124), - a housing (20) in which said measuring module is mounted, said housing (20) comprising on its upper wall (21) a fixing member (24) comprising a blocking wall (241) provided with an orifice (242), crossed by a part of the external portion (122) of the hollow tube and having an oblong shape, and at least one stop element (25), spaced from the blocking wall (241), the fixing head (124) having an oblong shape with dimensions smaller than those of the locking orifice (242) and comprising at one end a first locking portion (124A) and at a second end a second locking portion (124B), the first locking portion (124A) being locked between the locking wall (241) and the at least one stop element (25) and the second locking portion (124B) bearing against the locking wall (241).

2. Sensor (1) according to claim 1, wherein the fixing head (124) extends orthogonally to the longitudinal axis (X) of the external portion (122), the width of the fixing head (124) being equal to the diameter of the external portion (122) and the length of the fixing head (124) being in- less than or equal to the diameter of the orifice (242) of the fixing member (24) of the housing (20).

3. Sensor (1) according to any one of the preceding claims, in which the external portion (122) of the hollow rigid tube comprises, at its junction with the fixing head (124), an annular fixing groove (126) configured to receive a portion of the blocking wall (241).

4. Sensor (1) according to any one of claims 2 and 3, wherein the fixing head (124) comprises at least one relief shape (129) extending projecting from the first locking portion (124A) and / or from the second locking portion (124B), preferably from the first locking portion (124A) and from the second locking portion (124B).

5. Sensor (1) according to any one of the preceding claims, wherein the housing (20) comprises at least one reinforcement (26) supporting the at least one stop element (25) and / or the blocking wall (241).

6. A sensor (1) according to any preceding claim, wherein the housing (20) comprises at least one protrusion (245) extending projecting from the upper wall (21) of the housing (20) between the locking wall (241) and the at least one stop element (25).

7. The sensor (1) of claim 6, wherein at least one notch (128) is formed in at least one of the first locking portion (124A) or the second locking portion (124B).

8. Vehicle wheel, comprising a rim and a tire, equipped with at least one sensor (1) according to any one of the preceding claims.

9. Motor vehicle, comprising at least one wheel, said wheel comprising a rim and a tire and equipped with at least one sensor (1) according to any one of the preceding claims.

10. A method of assembling a sensor (1) according to any one of claims 1 to 6, said method comprising a step E1 of relative positioning of the valve body (110) relative to the housing (20), a step E2 of inserting the fixing head (124) into the orifice (242) of the blocking wall (241) of the housing (20), and a step E3 of rotating the fixing head (124) along the longitudinal axis (X) in order to block the first blocking portion (124A) between the blocking wall (241) and the at least one stop element (25) and the second blocking portion (124B) against the blocking wall (241).

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