Button cell battery sensor for automotive wheel

Abstract

The invention relates to a sensor (10) for a motor vehicle wheel, said sensor (10) being configured to be mounted on the rim of said wheel through a valve opening and comprising an electrically conductive curved wire spring (140) mounted in the lower part (112) of the sensor housing (110) and configured to hold a button cell battery (130) in said lower part (112) of the housing (110). Figure 2

Description

Title of the invention: Button cell battery sensor for motor vehicle wheel technical field

[0001] The present invention relates to the automotive field and more particularly concerns a button cell sensor, especially for a motor vehicle wheel, as well as a method of mounting such a sensor. Previous technique

[0002] Nowadays, it is common to mount a wheel sensor in each wheel of a motor vehicle in order to measure the temperature and pressure of the air contained in said wheel.

[0003] There are mainly two types of wheel sensors: band sensors and valve sensors.

[0004] A band sensor is glued inside the tread of a wheel tire, while a valve sensor has a valve and is mounted through the wheel valve opening formed in the rim.

[0005] A valve sensor includes, in a known manner, a housing in which is mounted a printed circuit board having electronic components enabling the measurement of values ​​of at least one parameter relating to the air contained in said wheel, such as, for example, temperature and / or pressure and / or acceleration.

[0006] The housing includes a valve body in the form of a tube adapted to be slid into the valve opening of the wheel in order to fix the sensor on the rim, for example using a screw and nut system or by instant snap-on, the free end of the valve body protruding outside the rim and being closed by a cap.

[0007] As is known, the sensor includes a battery for powering the components on the printed circuit board. Since the sensor must be able to withstand accelerations of several hundred g, it is known in existing solutions to solder the power supply battery.

[0008] However, such welding prevents the battery from being changed when said battery fails, which complicates battery recycling, and it is then necessary to throw away the entire sensor and replace it with a new one.

[0009] A simple, reliable and effective solution that would at least partially remedy these drawbacks would therefore be advantageous. Description of the invention

[0010] To this end, the invention first relates to a sensor for a motor vehicle wheel, said sensor being configured to be mounted on the rim of said wheel through a valve orifice and comprising: - a housing comprising an upper part and a lower part, said upper part comprising a tubular element configured to be placed in the valve opening of the rim and to receive the air for inflating the wheel tire, - a printed circuit board mounted in the upper part of the housing and comprising electronic components enabling the measurement of values ​​of at least one parameter relating to the air contained in said wheel, - a button cell battery mounted in the lower part of the casing and configured to electrically power said printed circuit board, - an electrically conductive curved wire spring mounted in the lower part of the casing and configured to hold the button cell battery in said lower part of the casing, the lower part of the housing comprising an internal surface from which extends at least one support element, configured to support a first face of the button cell, and the first and second retaining members of the wire spring, the wire spring comprising two arms connected by a central portion and configured to be positioned in an open position in which the two arms are detached from the second retaining members, allowing the button battery to be inserted onto at least one support element, and a closed position in which the central portion is fixed to the first retaining members and the two arms are fixed to the second retaining members and in which a first curved portion of each arm and a curved portion of the central portion of the wire spring press against the second face of the button battery, opposite the first face,and a second curved portion of each arm is in contact with an electrically conductive support area of ​​the printed circuit board to conduct the electric current between one of the terminals of the button cell and compress the wire spring when the upper and lower parts of the housing are assembled together and the printed circuit board is placed on the wire spring.

[0011] Using a button cell battery is a simple, inexpensive, reliable, and efficient way to power the wheel sensor. The button cell battery can be replaced when it is depleted. Using a wire spring to hold the button cell battery is a simple, reliable, and efficient way to keep the button cell battery securely in place within the sensor housing and thus withstand accelerations of several hundred g.

[0012] An obvious solution for a person skilled in the art would have been to use a spiral contact spring to ensure electrical contact with the battery. However, such spiral spring could move and cause power interruptions to the sensor when it is in operation and subjected to acceleration values ​​of several hundred g.

[0013] According to one aspect of the invention, a rechargeable button cell battery could be used.

[0014] Preferably, in the closed position, the two branches are fixed on the second retaining members at the level of their free ends.

[0015] Preferably, the sensor is configured so that in the open position, the central portion is fixed on the first retaining members.

[0016] In one embodiment, the lower part of the housing comprises two first retaining members.

[0017] Preferably, the first retaining organs each take the form of a lug.

[0018] In one embodiment, the lower part of the housing comprises two second retaining members.

[0019] Preferably, the second retaining organs each take the form of a lug.

[0020] In one embodiment, the lower part of the housing comprises three support elements extending from its internal surface.

[0021] Preferably, the sensor includes a contactor, made of an electrically conductive material, mounted in the lower part of the housing so as to come into contact with the other terminal of the button cell.

[0022] The invention also relates to a wheel for a motor vehicle, said wheel comprising a sensor as previously presented.

[0023] The invention also relates to a motor vehicle comprising at least one wheel as previously described.

[0024] The invention also relates to a method for mounting a sensor as described above, said method comprising the steps of: - separation of the lower and upper parts of the case, - placement of the button cell battery on at least one support element, - placement of the central portion of the wire spring on the first retaining members, - fixing the two arms of the wire spring on the second retaining members so that a first curved portion of each arm and a curved portion of the central portion of the wire spring press on the second face of the button cell, opposite the first face, and a second curved portion of each arm is in contact with an electrically conductive bearing area of ​​the printed circuit board to conduct the electric current between one of the terminals of the button cell and compress the wire spring when the upper and lower parts of the housing are assembled together and the printed circuit board is placed on the wire spring.

[0025] The invention also relates to a method for dismantling a sensor as described above, said method comprising the steps of: - separation of the lower and upper parts of the case, - removal of the two arms of the wire spring from the second set of retaining elements so as to place the wire spring in the open, released position, - removal of the button battery from at least one support element. Brief description of the drawings

[0026] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0027] [Fig-1] Fig. 1 schematically illustrates one embodiment of the vehicle according to the invention.

[0028] [Fig.2] Fig.2 is a partially exploded view of the lower and upper housings of a shape of the sensor according to the invention.

[0029] [Fig. 3] [Fig. 3] schematically illustrates the sensor of [Fig. 2] mounted on a rim of a motor vehicle wheel.

[0030] [Fig.4] [Fig.4] is a schematic transparent view of the lower part of the housing of an embodiment of a sensor according to the invention in which a button cell is mounted and held by a wire spring and a printed circuit board of an upper housing of said sensor positioned on said wire spring.

[0031] [Fig. 5] Fig. 5 is a three-quarter perspective view of the wire spring of the [Fig.4] in compressed position.

[0032] [Fig.6] Fig.6 is a top perspective view of the wire spring of Fig.4. relaxed position.

[0033] [Fig.7] Fig.7 is a front perspective view of the wire spring of Fig.4. relaxed position.

[0034] [Fig.8] Fig.8 is a side perspective view of the wire spring in the figure. relaxed position.

[0035] [Fig.9] Fig.9 is a top perspective view of the wire spring of Fig.4. compressed position.

[0036] [Fig. 10] The [Fig. 10] is a front perspective view of the wire spring of the [Fig.4] in the compressed position.

[0037] [Fig. 11] The [Fig. 11] is a side perspective view of the wire spring of the [Fig.4] in the compressed position. Description of the implementation methods

[0038] The figure illustrates an example of a motor vehicle 1 according to the invention.

[0039] The vehicle 1 comprises four wheels 5, each having a sensor 10 according to the invention.

[0040] With reference to [Fig.2], the sensor 10 comprises a housing 110, a printed circuit board 120, a button cell 130 and a wire spring 140.

[0041] The housing 110 comprising an upper part 111 and a lower part 112.

[0042] The upper part 111 includes a tubular element 111A placed, as illustrated in [Fig.3], in the valve opening 6 of the rim 7 and allowing to receive the inflation air of the tire 8 of the wheel 5. The tubular element 11 IA is closed by a plug 11 IB, in a manner known per se.

[0043] With reference to [Fig.2], the printed circuit board 120 is mounted in the upper part 111 of the housing 110 and includes electronic components (not visible) allowing the measurement of values ​​of at least one parameter relating to the air contained in the wheel 5 such as, for example, temperature and / or pressure.

[0044] With reference to figures 2 and 4, the printed circuit board 120 includes three electrically conductive support areas 121 intended to receive portions of the wire spring 140 in order to allow the electrical supply of the electronic components by the button cell 130.

[0045] The button cell 130 is mounted in the lower part 112 of the housing 110 and provides electrical power to the printed circuit board 120. For this purpose, the button cell 130 has, in a manner known per se, a first face 131 associated with a positive electrical terminal and a second face 132, opposite to the second face and associated with a negative electrical terminal.

[0046] The wire spring 140 is curved and electrically conductive. The wire spring 140 is mounted in the lower part 112 of the housing 110 and holds the button cell 130 in said lower part 112 of the housing 110 and against the printed circuit board 120.

[0047] Still with reference to figures 2 and 4, the lower part 112 of the housing 110 includes an internal surface 1120 from which extend three support elements 1121, first retaining members 1122 and second retaining members 1123.

[0048] Each support element 1121 is configured to support the first face 131 of the button cell 130.

[0049] In this example, the first retaining members 1122 are in the form of two lugs and the second retaining members 1123 are also in the form of two lugs.

[0050] The wire spring 140 comprises two branches 141 connected by a central portion 142.

[0051] Each branch 141 comprises a first curved portion 141-1, a second curved portion 141-2 and two free folded ends 141-3.

[0052] The central portion 142 includes a curved portion 142-1 in contact with the second face 132 of the button cell 130.

[0053] The wire spring 140 is configured to switch between an open position and a closed position. In the open position, the spring is relaxed as shown in Figures 6 to 8. In the closed position, the spring is compressed as shown in Figures 9 to 11.

[0054] In the open position, the central portion 142 is fixed on the first retaining members 1122 and the two arms 141 are raised, allowing the placement of the first face 131 of the button cell 130 on the support elements 1121.

[0055] In the closed, holding position, the central portion 142 is fixed to the first holding members 1122, the two arms 141 are fixed to the second holding members 1123, the first curved portion 141-1 of each arm 141 and the curved portion 142-1 of the central portion 142 bear against the second face 132 of the button cell 130, and the second curved portion 141-2 of each arm 141 is in contact with one of the electrically conductive bearing areas 121 of the printed circuit board 120 to conduct the electric current with the negative terminal of the button cell 130 and compress the wire spring 140 when the upper part 111 and the lower part 112 of the housing 110 are assembled together and the printed circuit board 120 is placed on the wire spring 140.

[0056] The sensor 10 includes a contactor 150, made of an electrically conductive material, mounted in the lower part 112 of the housing 110 so as to come into contact with the positive terminal of the button cell 130.

[0057] First, the lower part 112 of the housing 110 being separated from the upper part 111 of the housing 110 and the central portion 142 of the wire spring 140 being fixed on the first retaining members 1122, the wire spring 140 is placed in its open position and the button battery 130 is placed on the support elements 1121.

[0058] Next, the two arms 141 of the wire spring 140 are folded down and then fixed onto the second retaining members 1123 so that the first curved portion 141-1 of each arm 141 and the curved portion 142-1 of the central portion 142 of the wire spring 140 press on the second face 132 of the button cell 130 and that the second curved portion 141-2 of each arm 141 is in contact with the corresponding support area 121 of the printed circuit board 120 to conduct the electric current between one of the terminals of the button cell 130 and compress the wire spring 140 when the upper part 111 and the lower part 112 of the housing 110 are assembled together and the printed circuit board 120 is placed on the wire spring 140.

[0059] When disassembling the sensor to change the button cell battery 130, the lower part 112 of the housing 110 is separated from the upper part 111 of the housing 110 and the two branches 141 of the wire spring 140 are removed (or released) from the second retaining members 1123 so as to place the wire spring 140 in the open position.

[0060] The central portion 142 of the wire spring 140 can remain fixed on the first retaining members 1122 when the wire spring 140 is placed in its open position.

[0061] The button cell 130 is then removed from the support elements 1121 and from the lower part 112 of the housing 110 and replaced if necessary.

[0062] The invention therefore makes it possible to dismantle a power supply battery in a wheel sensor in a simple, quick, efficient, reliable and removable manner.

Claims

1. Demands Sensor (10) for a wheel (5) of a motor vehicle (1), said sensor (10) being configured to be mounted on the rim (7) of said wheel (5) through a valve opening (6) and comprising: - a housing (110) comprising an upper part (111) and a lower part (112), said upper part (111) comprising a tubular element (11 IA) configured to be placed in the valve opening (6) of the rim (7) and to receive the inflation air for the tire (8) of the wheel (5), - a printed circuit board (120) mounted in the upper part (111) of the housing (110) and comprising electronic components enabling the measurement of values ​​of at least one parameter relating to the air contained in said wheel (5), - a button cell battery (130) mounted in the lower part (112) of the housing (110) and configured to electrically power said printed circuit board (120),- an electrically conductive curved wire spring (140) mounted in the lower part (112) of the housing (110) and configured to retain the button cell (130) in said lower part (112) of the housing (110), the lower part (112) of the housing (110) having an internal surface (1120) from which extends at least one support element (1121), configured to support a first face (131) of the button cell (130), and first retaining members (1122) and second retaining members (1123) of the wire spring (140), the wire spring (140) comprising two arms (141) connected by a central portion (142) and being configured to be positioned in an open position in which the two arms (141) are detached from the second retaining members (1123), allowing the insertion of the button cell (130) onto the at least one element support (1121),and a closed position in which the central portion (142) is fixed to the first retaining members (1122) and the two arms (141) are fixed to the second retaining members (1123), and in which a first curved portion (141-1) of each arm (141) and a curved portion (142-1) of the central portion (142) of the wire spring (140) press against the second face (132) of the button cell (130), opposite the first face (131), and a second curved portion (141-2) of each arm, (141) is in contact with an electrically conductive support area (121) of the printed circuit board (120) to conduct the electric current between one of the terminals of the button cell (130) and compress the wire spring (140) when the upper part (111) and the lower part (112) of the housing (110) are assembled together and the printed circuit board (120) is placed on the wire spring (140).

2. Sensor (10) according to claim 1, wherein the lower part (112) of the housing (110) comprises two first retaining members (1122).

3. Sensor (10) according to any one of the preceding claims, wherein the first retaining members (1122) are each in the form of a lug.

4. Sensor (10) according to any one of the preceding claims, wherein the lower part (112) of the housing (110) comprises two second retaining members (1123).

5. Sensor (10) according to any one of the preceding claims, wherein the second retaining members (1123) are each in the form of a lug.

6. Sensor (10) according to any one of the preceding claims, wherein the lower part (112) of the housing (110) comprises three support elements (1121) extending from its inner surface.

7. Sensor (10) according to any one of the preceding claims, wherein the sensor (10) comprises a contactor (150), made of an electrically conductive material, mounted in the lower part (112) of the housing (110) so as to come into contact with the other terminal of the button cell (130).

8. Wheel (5) for motor vehicle, said wheel (5) comprising a sensor (10) according to any one of the preceding claims.

9. Motor vehicle (1) comprising at least one wheel (5) according to the preceding claim.

10. A method for mounting a sensor (10) according to any one of claims 1 to 7, said method comprising the steps of: - separating the lower part (112) and the upper part (111) of the housing (110), - placing the button cell battery (130) on at least one support element (1121), - placement of the central portion (142) of the wire spring (140) on the first retaining members (1122), - fixing the two arms (141) of the wire spring (140) to the second retaining members (1123) such that a first curved portion (141-1) of each arm (141) and a curved portion (142-1) of the central portion (142) of the wire spring (140) press against the second face (132) of the button cell (130), opposite the first face (131), and a second curved portion (141-2) of each arm (141) is in contact with an electrically conductive bearing area (121) of the printed circuit board (120) to conduct the electric current between one of the terminals of the button cell (130) and compress the wire spring (140) when the upper part (111) and the lower part (112) of the housing (110) are assembled together and the board of printed circuit board (120) is placed on the spring wire (140).

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