Sensor device for arranging in a tire

Abstract

The invention relates to a sensor device (10) for arranging in a tire, wherein the sensor device (10) has electronic components (20) and a housing (30) with a receiving space (31) and with a through-hole (32), wherein the electronic components (20) comprise at least one pressure sensor element (21) for measuring a tire pressure and are arranged within the receiving space (31), and wherein the pressure sensor element (21) is designed and arranged in such a way that, by means of the pressure sensor element (21) and via the through-hole (32), an ambient pressure of the housing (30) can be measured, wherein the housing (30) has a first material composition, and wherein protrusions (40), which project in particular into the receiving space (31) to support the electronic components (20), and / or a sealing element (50) between pressure sensor element (21) and through-hole (32) are formed within the housing (30), wherein the protrusions (40) and / or the sealing element (50) have a second material composition, wherein the second material composition has a lower elastic modulus than the first material composition.

Description

[0001] R. 415999

[0002] - 1 -

[0003] Description

[0004] Sensor device for arrangement in a tire

[0005] State of the art

[0006] A tire pressure monitoring system (TPMS) is an essential component of modern vehicles, used to measure and monitor tire pressure. Proper tire pressure significantly contributes to improving vehicle safety, efficiency, and driving comfort, while simultaneously extending tire lifespan. TPMS sensors are used not only in cars and trucks, but also in bicycles and bicycle trailers, for example. Data transmission from the TPMS sensor to an external receiver or device is typically wireless.

[0007] The prior art discloses sensor devices in which the electronic components of the sensor device are fixed inside the housing either by potting the housing or by welding a housing cover onto a housing base, and are thus protected from external influences.

[0008] In welded sensor devices of the prior art, the electronic components are first inserted into the housing base against hard stops and then clamped in place during the laser welding of the housing cover using small plastic pins, remaining in place for the entire service life of the sensor device. Furthermore, these sensor devices incorporate a sealing element to seal the pressure sensor against the plastic housing. This sealing element must be inserted or glued into the housing in a separate assembly step to secure it.

[0009] However, with this rigid mounting of the electronic components, there is a risk that temperature fluctuations in the field will cause the tensioned plastic pins to lose their preload and the seating of the electronic components in R. 415999

[0010] - 2 -

[0011] The casing develops play, which in turn can damage the electronic components due to vibrations.

[0012] The invention aims to solve, or at least reduce or optimize, the aforementioned problems in the prior art.

[0013] Disclosure of the invention

[0014] The invention relates to a sensor device for arrangement in a tire, wherein the sensor device comprises electronic components and a housing with a receiving chamber and a through-hole, wherein the electronic components comprise at least one pressure sensor element for detecting tire pressure and are arranged within the receiving chamber, and wherein the pressure sensor element is designed and arranged such that the ambient pressure of the housing can be detected by means of the pressure sensor element and via the through-hole, wherein the housing has a first material composition, and wherein projections extending into the receiving chamber for mounting the electronic components and / or a sealing element between the pressure sensor element and the through-hole are formed within the housing, wherein the projections and / or the sealing element have a second material composition.where the second material composition has a lower modulus of elasticity than the first material composition.

[0015] The advantage here is that, compared to a prior art device, the electronic components are softly mounted. This makes the sensor device resistant to vibration and durable. Furthermore, the soft sealing element ensures a reliable seal between the pressure sensor and the housing.

[0016] The sensor device is specifically designed as a tire pressure sensor and includes a corresponding pressure sensor element for detecting tire pressure. Tire pressure is understood to be the pressure in a tire filled with a medium, in particular air, which in turn typically corresponds to the ambient pressure of the sensor device housing, which is arranged inside the tire. R. 415999

[0017] - 3 - is. A tire can be from any means of transport with appropriately filled wheels, such as a car, truck, bicycle, or even an airplane. The sensor device typically includes, in addition to the actual pressure sensor element, other electronic components such as an electrical energy storage element, a circuit board, an accelerometer, or other sensor elements. Another example of an electronic component would be a processing unit, for example, an ASIC or a microcontroller, which can process data, such as measurement data from the pressure sensor element, and control other electronic components as needed. The pressure sensor element can be designed, for example, as a piezoelectric or capacitive sensor, which can, for example, convert the vibrations of a membrane into an electrical signal.Alternatively, a sensor with a different sensor principle is also conceivable. The pressure sensor element is designed and arranged in such a way that tire pressure can be detected using the pressure sensor element.

[0018] In particular, the pressure sensor element can be designed as a MEMS component.

[0019] A printed circuit board (PCB), also known as a printed circuit board, is a flat board made of insulating material on which conductive paths and connections for electronic components are mounted. The PCB serves as mechanical support and electrical connection for electronic components such as resistors, capacitors, transistors, integrated circuits, and other electronic parts. All electronic components, such as sensors and other necessary components like crystals, voltage regulators, and capacitors, can be mounted on the PCB.

[0020] An electrical energy storage element is a component that stores electrical energy and releases it when needed. The released energy can then be used, for example, to power a sensor unit. Examples of electrical energy storage elements include batteries, capacitors, and superconducting magnetic field storage devices. A lithium-ion battery (R. 415999) can be used as an example of a battery.

[0021] - 4 - which is designed, for example, as a button cell. However, any other battery is also conceivable, provided it is small enough and has the necessary supply voltage. Furthermore, both a secondary cell and a primary cell can be used as an energy storage element.

[0022] A housing is an outer casing or cover designed to protect and enclose electronic components, such as sensors or other parts. In this context, the housing refers to the outer casing of the sensor device, specifically designed for installation inside a tire. The housing contains a receiving chamber in which the electronic components, particularly the pressure sensor, are housed, and a through-hole that allows media exchange between the housing's environment and the receiving chamber, especially up to the pressure sensor. The housing is designed to protect the electronic components from external influences such as moisture, dirt, or mechanical damage. The housing specifically comprises a lid and a base. During manufacturing, the electronic components are inserted into the base or lid of the housing.Subsequently, the housing cover and base are joined together, particularly by a material-bonded connection, whereby no additional sealing element is introduced between the housing base and cover. A material-bonded connection refers to a bond in which two materials are connected by molecular or atomic forces. This type of connection is based on the attractive force between the molecules or atoms of the materials involved. Examples of material-bonded connections include welding, gluing, and soldering. A welding process, in particular, can be used for this purpose.

[0023] This allows a mechanically fixed connection to be created between the two housing parts.

[0024] Projections are raised areas or protruding parts that extend, in particular, from a surface of the housing. Specifically, these projections are the parts protruding within the housing of the sensor device that serve to mount the electronic components. These projections can be specially shaped to securely hold the electronic components and simultaneously comply with R. 415999.

[0025] - 5 -

[0026] To ensure the functionality and longevity of the sensor device, "bearing" refers to the positioning and securing of the electronic components within the sensor device. The protrusions serve to securely hold and position the electronic components, ensuring they are not damaged during operation. Proper bearing of the electronic components is essential for maintaining their functionality and reliability.

[0027] A sealing element is a component used to seal two adjacent surfaces or parts to prevent the ingress of liquids, gases, or other substances. The sealing element ensures that the housing is sealed and that any external medium can only reach the pressure sensor element, while protecting other electronic components. This is crucial for maintaining the functionality and accuracy of the pressure measurement. The sealing element can, in particular, be ring-shaped.

[0028] A material composition refers to the combination of different materials that are mixed or bonded together in a specific ratio to achieve particular properties. The material composition can influence various properties such as strength, elasticity, durability, weather resistance, chemical resistance, and other specific characteristics that are important for the functionality of the sensor device.

[0029] The modulus of elasticity, also known as the Young's modulus or the coefficient of elasticity, is a material constant that describes the stiffness and ductility of a material composition. It is a measure of a material's ability to deform under stress and then return to its original shape after unloading. The higher the modulus of elasticity of a material, the stiffer and less ductile it is. The modulus of elasticity is an important property in materials science and is often considered when selecting materials for specific applications. For example, the first material composition might be a hard plastic or metal, while the second material composition is designed to be softer than the first. R. 415999

[0030] - 6 -

[0031] One embodiment of the invention provides that the second material composition contains silicone.

[0032] The advantage here is that suitable damping properties can be achieved under vibrations and shock loads, and the necessary tightness of the sensor seal can be ensured throughout the service life of the sensor device. A silicone-containing material composition offers the particular advantages of low compression set and high restoring force.

[0033] The term "silicone-containing" means that the material contains or is silicone-based. Silicone is a synthetic polymer known for its versatile properties, such as heat resistance, flexibility, weather resistance, and chemical resistance. In this context, "silicone-containing" refers to the fact that the secondary material composition, used for the mounting surfaces for electronic components and / or for the sealing element, contains silicone as a component. Silicone-containing materials are often used in applications requiring flexibility, resistance to environmental influences, and sealing properties.

[0034] One embodiment of the invention provides that the housing and / or the projections and / or the sealing element are formed by means of an injection molding process.

[0035] The advantage here is that such a device can be manufactured with high precision and low production costs. In particular, if several or all elements, for example housing and projections or housing, projections and sealing element, are each manufactured using an injection molding process, the corresponding advantages of the process can be compounded.

[0036] First, the relevant housing elements can be injection-molded with a harder plastic material. Then, the protrusions and the sealing element can be molded into the housing elements using a softer material. R. 415999

[0037] - 7 - injection molded. In this process, the sealing element does not need to be glued or inserted separately, but can be injection molded onto the housing as a soft component in a single production step, including the protrusions. The electronic components can then be inserted into the housing elements, and finally, the housing elements can be joined and welded together.

[0038] This allows such a device to be manufactured cost-effectively and reliably.

[0039] Injection molding is a manufacturing process used to produce plastic parts. Molten material is injected into a mold where it hardens and takes on the desired shape.

[0040] A further embodiment of the invention provides that the housing has further projections for fixing the electronic components, wherein the further projections are formed within the housing, in particular projecting into the receiving space and in particular substantially opposite the projections, wherein the further projections have the first material composition.

[0041] The advantage here is that, despite the soft mounting of the electronic components, the additional protrusions press them against the soft protrusions or the sealing element, thus holding them in position throughout their service life. Even under vibration, the electronic components can still move slightly due to the soft mounting and therefore typically do not sustain damage.

[0042] The additional projections are also raised or protruding parts that, in particular, extend from a surface of the housing. These additional projections are specifically the parts protruding within the housing of the sensor device that serve to secure the electronic components. These additional projections can be specially shaped and arranged to secure the electronic components. In this context, the securing mechanism aims, in particular, to hold the electronic components within the housing in a stable and secure position. R. 415999

[0043] - 8 - Hold and press against the soft protrusions to ensure that the electronic components do not slip or become damaged during operation of the sensor device. In particular, the electronic components are secured when the housing cover and base are joined.

[0044] The additional projections are made of the same material as the housing itself and can therefore be manufactured together with the housing or as the housing itself. In particular, in this case, the additional projections are formed integrally with the rest of the housing.

[0045] According to a further embodiment of the invention, the housing has stop elements which are formed inside the housing, in particular projecting into the receiving space, wherein the stop elements have the first material composition.

[0046] The advantage here is that, despite the soft mounting of the electronic components, the housing cannot be compressed too much when an external force is applied to the sensor device, thus typically preventing damage to the electronic components even in this case. At the same time, this prevents excessive compression of the sealing element and thus blockage of the pressure channel due to excessive deformation. Therefore, pressure access through the through-hole and the sealing element is ensured under all load conditions, and the sealing element maintains a sufficiently large opening to transmit the applied pressure to the pressure sensor element.

[0047] A stop element is a component used to limit the movement or position of another component, such as the housing base or cover. These stop elements may extend beyond the projections or other protrusions. They are made of the same material as the housing itself and can be manufactured as part of the housing. In this case, the stop elements are specifically formed as a single piece with the rest of the housing. R. 415999

[0048] - 9 -

[0049] Drawings

[0050] Fig. 1 shows an embodiment of a sensor device according to the invention in a side sectional view.

[0051] Fig. 2 shows a first section of the embodiment of the sensor device according to the invention in a perspective view.

[0052] Fig. 3 shows a second section of the embodiment of the sensor device according to the invention in a perspective view.

[0053] Description of exemplary implementations

[0054] Fig. 1 shows an embodiment of a sensor device according to the invention in a side sectional view.

[0055] The figure shows a sensor device 10, which can, for example, be arranged in a tire. The sensor device comprises electronic components 20, which include, for example, a pressure sensor element 21 for detecting tire pressure, a circuit board 22, and a radio module 23, wherein the pressure sensor element 21 and the radio module 23 are arranged on the circuit board 22. Other electronic components 20, which are not shown here, could be, for example, an electrical energy storage element, a control unit, or components such as capacitors or resistors.

[0056] Furthermore, the sensor device 10 has a housing 30 with a receiving chamber 31 and a through-hole 32. The housing 30 is formed from a housing base 36 and a housing cover 37, which are connected to each other in a material-bonded and hermetically sealed manner, thus forming the receiving chamber 31 inside. The through-hole 32 is formed in the housing base 36 and allows access from the surroundings of the housing 30 to the receiving chamber 31. R. 415999

[0057] - 10 - electronic components 20 are arranged within the receiving space 31. In particular, the pressure sensor element 21 is designed and arranged such that the ambient pressure of the housing 30 can be detected by means of the pressure sensor element 21 and via the through-hole 32. The housing 30 has a first material composition.

[0058] Within the housing 30, projections 40, extending particularly into the receiving space 31, are formed to support the electronic components 20, and a sealing element 50 is formed between the pressure sensor element 21 and the through-hole 32. The two projections 40 shown on the right support the circuit board 20. The projection 40 shown on the left supports an energy storage element (not shown). The projections 40 and the sealing element 50 have a second material composition, the second material composition having a lower modulus of elasticity than the first. In particular, the second material composition contains silicone. The projections 40 and the sealing element 50 are arranged on the housing base 36.

[0059] Furthermore, the housing 30 has additional projections 33 for fixing the electronic components 20, wherein the additional projections 33 are located within the housing 30, in particular projecting into the receiving space 31 and, in particular, essentially opposite the projections 40. The additional projections 33 are correspondingly formed on the housing cover. This clamps the electronic components 20, such as the circuit board 22, between the additional projections 33 and the projections 40. The additional projections 33 have the first material composition.

[0060] Furthermore, the housing 30 has stop elements 34, which are formed within the housing 30, in particular projecting into the receiving space 31, wherein the stop elements 34 have the first material composition. The stop elements 34 are formed here on the housing base 36. In particular, the stop elements 34 can project at least partially beyond the projections 40. R. 415999

[0061] - 11 -

[0062] The housing 30, the projections 40, or the sealing element 50 are manufactured, for example, using an injection molding process.

[0063] Fig. 2 shows a first section of the embodiment of the sensor device according to the invention in a perspective view.

[0064] Shown is a section of the sensor device 10 from Fig. 1, which here shows the housing base 36 in a perspective view, looking into the receiving space 31 of the housing 30.

[0065] The projections 40, the sealing element 50, and the stop elements 34 are clearly visible. The sealing element 50 is located at the through-hole 32.

[0066] Fig. 3 shows a second section of the embodiment of the sensor device according to the invention in a perspective view.

[0067] Shown is a section of the sensor device 10 from Fig. 1, which here shows the housing cover 37 in a perspective view, again looking into the receiving space 31 of the housing 30.

[0068] The further projections 33 are clearly visible here.

Claims

R. 415999 - 12 - Claims 1. Sensor device (10) for arrangement in a tire, wherein the sensor device (10) comprises electronic components (20) and a housing (30) with a receiving chamber (31) and a through-hole (32), wherein the electronic components (20) comprise at least one pressure sensor element (21) for detecting tire pressure and are arranged within the receiving chamber (31), and wherein the pressure sensor element (21) is designed and arranged such that the ambient pressure of the housing (30) can be detected by means of the pressure sensor element (21) and via the through-hole (32), wherein the housing (30) has a first material composition, and wherein projections (40) for mounting the electronic components (20) and / or a sealing element (50) between the pressure sensor element (21) and the through-hole (32) are formed within the housing (30), in particular projecting into the receiving chamber (31).wherein the projections (40) and / or the sealing element (50) have a second material composition, the second material composition having a lower modulus of elasticity than the first material composition.

2. Sensor device (10) according to claim 1 , characterized in that the second material composition is silicone-containing.

3. Sensor device (10) according to one of the preceding claims, characterized in that the housing (30) and / or the projections (40) and / or the sealing element (50) are formed by means of an injection molding process.

4. Sensor device (10) according to one of the preceding claims, characterized in that the housing (30) has further projections (33) for fixing the electronic components (20), wherein the further projections (33) are formed within the housing (30), in particular projecting into the receiving space (31) and in particular substantially opposite the projections (40), wherein the further projections (33) have the first material composition. R. 415999 - 13 - 5. Sensor device (10) according to one of the preceding claims, characterized in that the housing (30) has stop elements (34) which are formed inside the housing (30), in particular projecting into the receiving space (31), wherein the stop elements (34) have the first material composition.

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