Tire pressure sensor and inflating valve

Abstract

The invention relates to a tire pressure sensor and an inflating valve. The tire pressure sensor comprises a printed circuit board, a battery and a helical antenna assembly, the printed circuit board, the battery and the helical antenna assembly are subjected to an injection molding process to obtain a sensor assembly, the helical antenna assembly comprises an antenna support and a helical antenna arranged on the outer side wall of the antenna support, the interior of the antenna support is hollow, and the helical antenna is arranged in the antenna support. A spiral groove is formed in the outer side wall of the antenna support, the spiral antenna is wound in the spiral groove, a plurality of buckles for fixing the circuit board are arranged at the bottom of the antenna support, and a pressure sensing piece and an antenna matching circuit are printed on the printed circuit board. And the antenna matching circuit is used for transmitting a radio frequency signal output after the tire pressure signal sensed by the pressure sensing piece is modulated to the input end of the helical antenna. The tire pressure sensor is smaller in size, lighter in weight and compact in structure, and stable signal transmission can be achieved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a tire pressure sensor and a valve stem. Background Art

[0002] This application claims priority to Chinese patent application number 202221724815.0, filed on July 6, 2022, which was published on August 9, 2022, with publication number CN217158622U, and published in Chinese. The Chinese patent application is hereinafter referred to as the priority application of this application.

[0003] TPMS (Tire Pressure Monitor System) is the full name of tire pressure monitoring system. The function of TPMS is to automatically monitor the tire pressure in real time while the car is driving, and to alarm for tire leakage and low pressure to ensure driving safety. TPMS mainly includes tire pressure sensor (or TPMS sensor), MCU (Microcontroller Unit), RF module and antenna.

[0004] At present, tire pressure sensors are usually wireless sensors, that is, after collecting relevant signals of tire pressure and other parameters, the tire pressure sensor will encode and modulate them into radio frequency signals and transmit them through the antenna, so that the receiving device of the vehicle system can receive the radio frequency signal and decode it to obtain the parameter value collected by the tire pressure sensor. Among them, the antenna, as a key component in the tire pressure sensor, is crucial to the sensor's radio frequency signal transmission efficiency and operating stability.

[0005] In the related art, IFA, PIFA, loop antenna (i.e., the antenna includes a signal feed point, and the end of the antenna is directly connected to the ground or AC ground) and other types of antennas are usually used. However, these types of antennas are usually large in size. Accordingly, due to the limitation of such large-size antennas, tire pressure sensors are usually large in size and heavy in weight, which brings many inconveniences to the production and use process. In addition, traditional TPMS sensors usually assemble various components in a prefabricated housing. Due to the small space of the housing, the assembly steps are complicated and the efficiency is low. There may be gaps between the assembled components, which makes the sensor difficult to withstand vibration, affecting the signal transmission stability of the sensor and even causing damage. Summary of the invention

[0006] In view of this, in order to solve the problems existing in the above-mentioned related technologies, the present application proposes a tire pressure sensor and a tire valve. The technical solution of the present application is as follows:

[0007] According to a first aspect of an embodiment of the present application, a tire pressure sensor is provided, comprising: a sensor assembly obtained by an injection molding process from a printed circuit board, a battery, and a helical antenna assembly, wherein:

[0008] The battery pins of the battery are respectively connected to the corresponding power supply pins of the printed circuit board;

[0009] The helical antenna assembly comprises an antenna bracket and a helical antenna arranged on the outer side wall of the antenna bracket, the antenna bracket is hollow inside, a helical groove is arranged on the outer side wall of the antenna bracket, the helical antenna is wound in the helical groove, and a plurality of buckles for fixing the circuit board are arranged at the bottom of the antenna bracket;

[0010] The printed circuit board is printed with a pressure sensing component and an antenna matching circuit, and the antenna matching circuit is used to transmit the radio frequency signal output after the pressure sensing component modulates the sensed tire pressure signal to the input end of the helical antenna.

[0011] Optionally, the battery pins of the battery are respectively connected to corresponding power supply pins of the printed circuit board.

[0012] Optionally, the injection molding process forms a protective body covering the printed circuit board, the battery and the helical antenna assembly, and air holes are provided on the protective body at positions corresponding to the pressure sensing holes of the pressure sensing component.

[0013] Optionally, it also includes a base and a shell installed on the base, a sealed cavity for accommodating the sensor assembly is formed between the base and the shell, a pressure transmission hole connected to the sealed cavity is opened on the base, and a gas channel connecting the pressure transmission hole and the air hole is formed in the sealed cavity.

[0014] Optionally, the gas channel is formed by sequentially connecting a first gas channel, a second gas channel, and a third gas channel, wherein:

[0015] The first gas channel is formed between the end surface of the protective body facing the base and the bottom surface of the base;

[0016] The second gas channel is formed between the outer wall of the protective body and the inner wall of the shell;

[0017] The third gas channel is formed between the end surface of the protective body away from the base and the inner wall of the end of the shell.

[0018] Optional,

[0019] A plurality of protrusions are formed on the end surface of the protective body facing the base, and the protrusions form the first gas channel between the protective body and the bottom surface of the base;

[0020] A plurality of grooves are formed on the inner wall of the shell, and the grooves form the second gas channel between the outer wall of the protective body and the inner wall of the shell; and / or,

[0021] A notch is formed on the end surface of the protection body away from the base, and the notch forms the third gas channel between the protection body and the inner wall of the end of the shell.

[0022] Optional,

[0023] The absolute value of the difference between the angle between the gas flow directions of the second gas channel and the first gas channel and 90° is not greater than a first threshold; and / or,

[0024] An absolute value of a difference between an angle between gas flow directions of the second gas channel and the third gas channel and 90° is not greater than a second threshold.

[0025] Optionally, a buffer recessed portion communicating with the air hole is further formed on the end surface of the protective body away from the base.

[0026] Optionally, the helical antenna and the pressure sensing holes on the pressure sensing element are both facing a side away from the base.

[0027] Optionally, the printed circuit board, the battery and the helical antenna assembly are integrally formed by an injection molding process to obtain the sensor assembly; or,

[0028] The printed circuit board, the battery and the helical antenna assembly are obtained through an injection molding process to obtain a plurality of injection molding accessories, and the plurality of injection molding accessories are spliced ​​into the sensor assembly.

[0029] Optionally, the injection molding process is a low-pressure injection molding process.

[0030] Optionally, the injection molding material of the low-pressure injection molding process is thermoplastic polyamide.

[0031] Optionally, the pressure sensing element is a sensor chip integrated with a pressure sensing device.

[0032] Optionally, the sensor chip is also integrated with a temperature sensing device, an acceleration sensing device and / or an angle sensing device.

[0033] Optionally, the radio frequency signal outputted by the pressure sensing element after modulating the sensed tire pressure signal includes:

[0034] The tire pressure signal is subjected to frequency shift keying (FSK) modulation to output an FSK signal; or,

[0035] ASK signal output after ASK modulation of tire pressure signal

[0036] Optionally, the helical antenna includes a first pin and a second pin, the first pin serves as an input end of the helical antenna, and the second pin is suspended, wherein:

[0037] The antenna bracket is provided with an axial groove, and a welding hole is provided at a position vertically corresponding to the axial groove on the printed circuit board, and the first pin passes through the welding hole and is welded to the output end of the antenna matching circuit.

[0038] Optionally, the battery is a button battery with specifications of BR1632, CR1632, BR1620, CR1620, BR1225, CR1225, BR1220 or CR1220.

[0039] According to a second aspect of an embodiment of the present application, a valve is provided, on which a tire pressure sensor as described in any one of the first aspects is mounted.

[0040] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0041] The printed circuit board, battery and helical antenna assembly in the tire pressure sensor described in the present application are obtained by an injection molding process to obtain a sensor assembly; in addition, a pressure sensing component and an antenna matching circuit are printed on the printed circuit board, and the circuit is respectively connected to the pressure sensing component and the helical antenna. After the pressure sensing component senses the tire pressure and modulates the output radio frequency signal, it is tuned and impedance converted by the antenna matching circuit and emitted to the surrounding space through the helical antenna.

[0042] It can be seen that, on the one hand, this solution abandons the large-size antennas such as IFA, PIFA, loop antenna, etc. commonly used in related technologies, and instead adopts the spiral antenna disclosed in the priority application as the antenna in the tire pressure sensor. Compared with the traditional TPMS sensor using the aforementioned large-scale antenna, it is possible to miniaturize the tire pressure sensor, making it smaller in size and lighter in weight, and the parameters of the antenna matching circuit and the spiral antenna can be adjusted during the production stage, so that the radio frequency signal emitted by the tire pressure sensor has a higher bandwidth and excellent gain characteristics, thereby achieving more stable and efficient signal transmission. On the other hand, during the production stage, the sensor assembly is obtained through an injection molding process, which makes the overall structure and assembly steps of the sensor assembly simple, and can ensure that the internal structure of the finally assembled tire pressure sensor is compact, so that the sensor is more resistant to vibration and the signal transmission stability is also higher.

[0043] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 , Figure 2 and Figure 3 Figure 2 is a structural diagram of the helical antenna assembly.

[0046] Figure 4 This is a schematic diagram of the assembly structure of the tire pressure sensor and valve stem disclosed in this application.

[0047] Figure 5 This is an exploded view of the tire pressure sensor and valve stem disclosed in this application.

[0048] Figure 6 This is a schematic structural diagram of the housing of the tire pressure sensor disclosed in this application.

[0049] Figure 7 a, b, and c are respectively a three-dimensional view, a top view, and a bottom view of the sensor assembly in the tire pressure sensor disclosed in the present application.

[0050] Figure 8 The figure is an exploded view of the sensor assembly in the tire pressure sensor disclosed in the present application.

[0051] Fig. 9 The schematic diagram is a schematic diagram of an antenna matching circuit printed on a printed circuit board in the tire pressure sensor disclosed in the present application.

[0052] In the above drawings, the structures are numbered as follows: helical antenna 1, first pin 11, second pin 12; antenna bracket 2, buckle 21, helical groove 22, axial groove 23, wedge groove 24, stopper 25; printed circuit board 3, pressure sensing component 31, pressure sensing hole 311, antenna matching circuit 32, welding hole 33, pin through hole 34, buckle recess 35; battery 4, battery pin 41; protective body 5, air hole 51, protrusion 52, notch 53, buffer recess 54; base 6, pressure transmission through hole 61, flange 62, sealing ring 63; housing 7, groove 71, step 72; valve 8, connecting nut 81, thread 82, valve cap 83; sensor assembly 9, helical antenna assembly 10. Among them, the helical antenna assembly 10 is the helical antenna assembly described in the priority application. DETAILED DESCRIPTION

[0053] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0054] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0055] The tire pressure sensor disclosed in the present application comprises: a sensor assembly 9 obtained by injection molding of a printed circuit board 3, a battery 4 and a helical antenna assembly 10, wherein:

[0056] The battery pins 41 of the battery 4 are respectively connected to the corresponding power supply pins of the printed circuit board 3;

[0057] The helical antenna assembly 10 includes an antenna bracket 2 and a helical antenna 1 arranged on the outer wall of the antenna bracket 2. The antenna bracket 2 is hollow inside, and a spiral groove 22 is provided on the outer wall of the antenna bracket 2. The helical antenna 1 is wound in the spiral groove 22. A plurality of buckles 21 for fixing the circuit board are provided at the bottom of the antenna bracket 2. A pressure sensing component 31 and an antenna matching circuit 32 are printed on the printed circuit board 3. The antenna matching circuit 32 is used to transmit the radio frequency signal output after the pressure sensing component 31 modulates the sensed tire pressure signal to the input end of the helical antenna 1.

[0058] The printed circuit board 3, battery 4 and helical antenna assembly 10 in the tire pressure sensor described in the present application are obtained by an injection molding process to obtain a sensor assembly 9; in addition, a pressure sensing component 31 and an antenna matching circuit 32 are printed on the printed circuit board 3, and the circuits are respectively connected to the pressure sensing component 31 and the helical antenna 1. After the pressure sensing component 31 senses the pressure inside the tire and modulates the output radio frequency signal, it is tuned and impedance converted by the antenna matching circuit 32 and transmitted to the surrounding space through the helical antenna 1.

[0059] It can be seen that, on the one hand, this solution abandons the large-size antennas such as IFA, PIFA, loop antenna, etc. commonly used in the related art, and instead adopts the spiral antenna 1 disclosed in the priority application as the antenna in the tire pressure sensor. Compared with the traditional TPMS sensor using the aforementioned large-scale antenna, it is possible to miniaturize the tire pressure sensor, making it smaller in size and lighter in weight, and the parameters of the antenna matching circuit 32 and the spiral antenna 1 can be adjusted during the production stage, so that the radio frequency signal emitted by the tire pressure sensor has a higher bandwidth and excellent gain characteristics, thereby achieving more stable and efficient signal transmission. On the other hand, during the production stage, the sensor assembly 9 is obtained by an injection molding process, so that the overall structure and assembly steps of the sensor assembly 9 are simple, and it can ensure that the internal structure of the finally assembled tire pressure sensor is compact, so that the sensor is more resistant to vibration and the signal transmission stability is also higher.

[0060] In this solution, the printed circuit board 3, the battery 4 and the helical antenna assembly 10 are formed into the sensor assembly 9 by injection molding. Figure 7 As shown in a, the outermost protective body 5 of the sensor assembly 9 is obtained by injection molding. Specifically, the sensor assembly 9 can be obtained by injection molding in a variety of ways.

[0061] For example, for the printed circuit board 3, the battery 4 and the helical antenna assembly 10 (assembled by the helical antenna 1 and the antenna bracket 2), a plurality of injection molded parts can be obtained by injection molding, and then the plurality of injection molded parts can be spliced ​​into the sensor assembly 9. Among them, the connection method between the plurality of injection molded parts can include but is not limited to glue bonding, threaded connection, snap-on connection, secondary injection molding of the injection molded parts to melt the contact surface and then bond, etc., and this specification does not limit this. It can be understood that each of the above-mentioned injection molded parts has a corresponding coating part (that is, the part coated on the periphery of the corresponding component obtained by the solidification of the injection molding material after the injection molding is completed), and after the connection is completed, the coating parts of each injection molded part are also connected to each other to form the protective body 5 as a whole. In addition, any injection molded part can include at least one part. For example, the helical antenna assembly 10 itself can be injection molded to obtain a first injection molded part, and the printed circuit board 3 and the battery 4 can be injection molded to obtain a second injection molded part, and then the two can be connected into a whole according to the positional relationship of the first injection molded part on the top and the second injection molded part on the bottom, and the whole is the sensor assembly 9. Of course, the printed circuit board 3, the battery 4 and the helical antenna assembly 10 can also be injection molded separately to obtain three injection molded parts, and then the three can be connected to form the sensor assembly 9. This specification does not limit the total number of injection molded parts and the specific components included in any of the multiple injection molded parts. A reasonable selection can be made based on actual conditions such as processing difficulty, error requirements, processing efficiency, etc., and will not be repeated here.

[0062] For another example, the printed circuit board 3, the battery 4 and the helical antenna assembly 10 (assembled from the helical antenna 1 and the antenna bracket 2) can also be integrally formed through an injection molding process to obtain the sensor assembly 9. In this way, the protective body 5 covering the printed circuit board 3, the battery 4 and the helical antenna assembly 10 can be formed through one-time injection molding. The injection molding process has relatively fewer steps, and the overall structure of the sensor assembly 9 obtained by injection molding is also more compact. During the production process of the sensor assembly 9, the printed circuit board 3, the battery 4 and the helical antenna assembly 10 can be placed in an injection mold according to a pre-designed relative position relationship, and the injection molding operation can be performed. The relative position relationship is as follows: Fig. 9 As shown. After the injection molding is completed, the protective body 5 covering the printed circuit board 3, the battery 4 and the helical antenna assembly 10 is formed at one time. At this time, the protective body 5 and the printed circuit board 3, the battery 4 and the helical antenna assembly 10 covered therein are collectively referred to as the sensor assembly 9. Obviously, because the protective body 5 can completely cover the printed circuit board 3, the battery 4 and the helical antenna assembly 10 therein, the sensor assembly 9 with a compact internal structure can be generated with a relatively smaller assembly volume (the assembly volume is equal to the volume of the protective body 5), and the internal components can be waterproof (such as meeting the waterproof requirements of IP67, IP69K, etc.), dustproof, vibration-proof, high-pressure resistant and other beneficial effects can be achieved, and the tire pressure sensor has a high degree of integration, which is suitable for mass production, and the assembled tire pressure sensor has stable signals and high reliability, and can work normally under various harsh working conditions.

[0063] In one embodiment, a pore 51 may be provided at a position on the protective body 5 corresponding to the pressure sensing hole 311 of the pressure sensing element 31. The pore 51 is used to guide the gas (transmitted through the gas channel described below) to the pressure sensing hole 311 on the pressure sensing element 31, so that the pressure sensing device inside it can sense and detect the gas pressure. Alternatively, in addition to providing the pore 51 on the protective body 5, during injection molding, the end face of the protective body 5 away from the base 6 may not be produced, that is, an opening is formed at the cross-section position to facilitate gas transmission. The pore 51 is still used as an example for explanation below.

[0064] Furthermore, the injection molding process can adopt a low-pressure injection molding (LPM) process. Compared with the traditional high-pressure injection molding process (HLM), the melting point and viscosity of the injection molding material (such as hot melt adhesive) used in the low-pressure injection molding process are lower, so the injection temperature and injection pressure required for the low-pressure injection molding process are also lower. For example, the injection temperature of the low-pressure injection molding process only needs 190 to 230°C, which is significantly lower than the injection temperature of the high-pressure injection molding process (230 to 300°C); the injection pressure of the low-pressure injection molding process only needs 1.5 to 40 bar. Therefore, the present application adopts a low-pressure injection molding process for injection molding and production of sensor components, which can avoid the adverse effects or even damage of high temperature and high pressure on the helical antenna component 10, the printed circuit board 3 and the battery 4, thereby improving the yield rate of the sensor component 9 to a certain extent.

[0065] Among them, the low-pressure injection molding process can select injection molding materials with excellent mechanical properties (such as being strong and having certain elasticity, waterproof, heat insulation, flame retardant, etc.) and electrical properties (such as insulation, low dielectric constant, etc.). Exemplarily, thermoplastic polyamide can be used as the injection molding material, such as thermoplastic polyamide with the model TECHNOMELT PA 646 (e). Because the material has low viscosity, it can be processed and used under relatively low pressure to achieve injection molding, which can not only seal and package the sensor without damaging the internal components, but also does not produce toxic fumes during the processing process, which is safer and more user-friendly. Of course, other types and other types of injection molding materials can also be selected according to actual conditions, and this application does not limit this. In addition, given that the injection molding material usually has a relative dielectric constant, and this parameter will affect the signal of the helical antenna 1. Given that the relative dielectric constant of polyamide produced by different manufacturers, batches, processes and other production environments may be different, so in combination with the aforementioned antenna matching circuit 32, the dielectric constant can be used as a parameter of the polyamide for reasonable selection, for example, a polyamide with a dielectric constant value less than 4.2 can be used as an injection molding material.

[0066] The assembly structure of the tire pressure sensor and the valve can be found in Figure 4 .like Figure 4 As shown, a base 6 is provided on the valve 8, a housing 7 is installed in the base 6, and a sealed cavity for accommodating a sensor assembly 9 is formed between the base 6 and the housing 7. For a detailed exploded view of the structure, see Figure 5 .like Figure 5 As shown, the base 6 is provided with a pressure transmission hole 61, which is connected to the air cavity (not shown) that passes through the valve 8, and a gas passage connecting the pressure transmission hole 61 and the air hole 51 is formed in the sealed cavity. The valve 8 can be connected to the vehicle tire through a connecting nut 81, for example, the connection can be achieved by the connection nut 81 and the thread on the original valve of the tire. After the connection is completed, the pressure transmission hole 61 is connected to the inside of the vehicle tire through the air cavity.

[0067] The other end of the valve 8 away from the connecting nut 81 may also be provided with a thread 82, which can be used to connect other devices to facilitate functional expansion. For example, after the valve 8 is connected to the tire through the connecting nut 81, it can be expanded through the thread 82 to inflate, deflate, connect to other external detection devices, etc. Obviously, by providing the thread 82, it is unnecessary to remove the valve 8 during actual use (i.e., it is unnecessary to disconnect the connection between the connecting nut 81 and the original valve of the tire), and the extended function can be achieved on the basis of the valve 8, which is more convenient for users to use.

[0068] In addition, it can be seen from the above structure that after the tire pressure sensor is assembled, the valve 8 and the sensor assembly 9 form a three-way structure for gas with the pressure transmission hole 61 as the center. Figure 5 The valve 8 (and the air cavity therein) is shown as a straight line. It is understandable that the straight line is only one of the feasible implementations of the three-way structure. In the implementation of the solution, the valve 8 can also adopt other shapes. This specification does not limit the specific shape of the three-way structure. For example, Figure 5 The valve 8 shown can be divided into a first part close to the connection nut 81 and a second part close to the thread 82 with the pressure transmission hole 61 as the dividing point. For the above two parts, the first part can be deflected 90° in the direction away from the base 6 with the pressure transmission hole 61 as the center, so that the center line of the air cavity inside the second part coincides with or approaches the center line of the sensor assembly 9 after the deflection, thereby transforming the shape of the valve 8 itself into an L shape, and the valve 8 and the third part form a T shape as a whole. In this way, on the one hand, it can be ensured that the second part after deflection can still normally realize the above-mentioned extended function; on the other hand, the second part after deflection and the third part where the base is located (including the base 6, the sensor assembly 9 and the shell 7) are respectively located on both sides of the center line of the internal air cavity of the first part, that is, the second part and the third part are symmetrical with each other around the center line of the internal air cavity of the first part, so that the weight of the two can offset each other (at least partly), so that the center of gravity of the valve stem 8 equipped with the tire pressure sensor is located on the center line of the internal air cavity of the first part (or as close to the center line as possible), thereby avoiding wear on one side of the tire caused by the valve stem 8 installed on the tire being biased to one side.

[0069] The base 6 is generally made of metal. In addition, to ensure that the base 6 is firmly connected to the valve 8, the base 6 can be welded or threaded with the valve 8, or even integrally formed with the valve 8 during the production of the valve 8, which will not be described in detail.

[0070] The shell 7 is installed on the base 6, and a sealed cavity for accommodating the sensor assembly 9 is formed between the base 6 and the shell 7, and the sealed cavity is connected to the pressure transmission through hole 61; the sensor assembly 9 is located in the sealed cavity, and a gas channel connecting the pressure transmission through hole 61 and the air hole 51 is formed in the sealed cavity.

[0071] like Figure 1 , Figure 2 and Figure 3 As shown, the helical antenna assembly 10 includes an antenna bracket 2 and a helical antenna 1 arranged on the outer wall of the antenna bracket 2. The antenna bracket 2 is hollow inside, and a spiral groove 22 is provided on the outer wall of the antenna bracket 2. The helical antenna 1 is formed and wound in the spiral groove 22, that is, the helical antenna 1 and the antenna bracket 2 are assembled as a whole.

[0072] In some practical applications, the antenna bracket 2 can be produced in advance, and then a wire is used to wind along the spiral groove 22 on the antenna bracket 2. The winding process can be completed manually or automatically by a machine. After the winding is completed, the spiral antenna 1 is assembled with the antenna bracket 2. Alternatively, the spiral antenna 1 and the antenna bracket 2 can also be integrally formed by an injection molding process. For example, the spiral antenna 1 can be placed in an injection mold for injection molding. After the injection molding is completed, the antenna bracket 2 is formed, and the spiral antenna 1 surrounds the antenna bracket 2. A buckle 21 for fixing the circuit board can be provided at the bottom of the antenna bracket 2. The buckle 21 can be radially symmetrically arranged. The buckle 21 can be provided with hooks facing each other toward the axis, and the circuit board is hooked by the hook. The bottom of the hook can be wedge-shaped, and a plurality of adjacent wedge-shaped hooks form a guide slot for guiding the installation of the circuit board, making the installation more convenient. Among them, the number of the buckles 21 can be at least two (such as 2, 4, 6, etc.). Of course, it can also be an odd number (such as 5, 3, etc.) and evenly arranged along the ring, and the present application does not limit this.

[0073] The outer wall of the antenna bracket 2 is provided with an axial groove 23 that runs through the upper and lower ends, the axial groove is connected to the spiral groove, and the first pin 11 of the spiral antenna 1 is adapted to the axial groove 23. The upper end of the antenna bracket 2 is provided with a stopper 25 for adapting the spiral antenna. In this way, one end of the spiral antenna 1 is bent and cooperates with the stopper 25 for positioning, and the other end is positioned by the cooperation of the first pin 11 and the axial groove 23, which can conveniently realize the positioning of the spiral antenna 1 on the antenna bracket 2.

[0074] The upper end of the antenna support 2 may be provided with a wedge-shaped groove 24 for adapting the helical antenna. The line pitch range of the helical groove 22 may be not less than 0.8 mm (millimeter, the same below) and not more than 1.5 mm.

[0075] In one embodiment, the helical antenna 1 is formed by winding a wire. While ensuring that the sensor has good signal strength, in order to control the volume of the helical antenna 1 to achieve miniaturization of the sensor, a wire with a diameter of not less than 0.3 mm and not more than 0.7 mm can be selected, and the number of turns of the wire can be not less than 2 and not more than 5. In addition, the material of the wire can be copper, so as to use the excellent conductivity of copper to achieve a better signal transmission effect.

[0076] In one embodiment, the pressure sensing element may also have an MCU and a signal modulation module, wherein the MCU is used to control the operation of the tire pressure sensor and process the collected pressure signal, such as inputting the collected pressure signal into the signal modulation module in the form of binary data, so that the module loads the pressure signal to the carrier signal through a modulation process to obtain a radio frequency signal, and outputs the radio frequency signal to the input end of the antenna matching circuit 32, so that it is tuned and impedance-converted by the antenna matching circuit 32 and transmitted to the surrounding space through the helical antenna 1. In this way, the modulated output radio frequency signal can be used to transmit the collected tire pressure signal to the antenna matching circuit 32.

[0077] In one embodiment, the pressure sensing element 31 can modulate the sensed tire pressure signal in various forms and output a corresponding radio frequency signal. For example, the tire pressure signal can be modulated by FSK (Frequency ShiftKeying) and the modulated FSK signal can be output. For another example, the tire pressure signal can be modulated by ASK (Amplitude Shift Keying) and the modulated ASK signal can be output.

[0078] In one embodiment, the pressure sensing element 31 may be a sensor chip, and a pressure sensing device may be integrated in the chip. According to different principles of pressure sensing, the pressure sensing device may be in various forms, for example, it may be a piezoresistive sensing device, a strain sensing device (or strain gauge), a piezoelectric sensing device, a piezoceramic sensing device, a potential sensing device, etc., and the present application does not limit this. In addition, at least one signal modulation circuit (such as the aforementioned signal debugging module) may be integrated in the sensor chip, so that the chip can work in different modes as needed to output a modulated signal in a corresponding form. For example, assuming that the sensor chip is internally integrated with an FSK modulation module (corresponding to the FSK mode) and an ASK modulation module (corresponding to the ASK mode), during the operation of the tire pressure sensor, if the collected tire pressure signal needs to be FSK modulated, the chip should work in the FSK mode so as to call its internal FSK modulation module to perform FSK modulation on the tire pressure signal to obtain an FSK signal and output it. The specific working mode of the sensor chip may correspond to the antenna matching circuit to which it is connected, and the working mode of the sensor chip may be set at an appropriate time before or after the sensor chip is printed on the printed circuit board. Figure 8 As shown, a pressure sensing hole 311 can be provided at a position on the pressure sensing member 31 corresponding to the pressure sensing device (not shown). The pressure sensing hole 311 is connected to the interior of the tire through a gas channel, so that the internal pressure of the tire can be transmitted to the pressure sensing hole and sensed by the pressure sensing device thereunder, thereby realizing pressure detection.

[0079] Furthermore, the sensor chip may also be integrated with a temperature sensing device, an acceleration sensing device and / or an angle sensing device, so that the tire pressure sensor can detect physical parameters such as tire temperature, acceleration and / or angle while detecting tire pressure, so as to realize the functional integration of a single sensor, thereby helping to reduce the number of sensors. Among them, because the tire will rotate around the axis during the driving process of the vehicle, and the relative angle between the plane where the circular contour of the tire is located and the ground can reflect the direction, inclination, etc. of the tire, the position of the angle sensing device in the tire pressure sensor can be reasonably set to accurately detect the above-mentioned angle of the tire, thereby providing direct data support for the vehicle system to obtain the vehicle steering angle, left and right inclination and other states.

[0080] For example, sensor chips such as MLX91804, SP40T, NTM88xxx5, etc. can be used as the pressure sensing element 31. Such sensor chips also integrate the detection function of other parameters such as temperature, thereby reducing the number of electrical components that need to be printed on the printed circuit board 3 through functional integration, further saving the valuable space of the printed circuit board 3, and helping to achieve miniaturization. In addition, the signals output by the aforementioned temperature sensing device, acceleration sensing device and / or angle sensor can also be modulated into radio frequency signals and output by the aforementioned signal modulation module, which will not be repeated.

[0081] Fig. 9 3 is a schematic diagram of the antenna matching circuit 32. Fig. 9 As shown, taking FSK modulation as an example, "FSK RF OUT" represents the signal output end of the pressure sensing component 31, which is used to output the modulated FSK signal (the FSK signal is essentially a radio frequency signal). As mentioned above, when the pressure sensing component 31 is a pressure sensor chip, the chip can operate in FSK mode. In fact, it is also possible to build a pressure sensing circuit on the printed circuit board 3 through independent electronic components (such as independent piezoelectric sheets, resistors, capacitors, inductors, wires, etc.), so that the circuit can realize the pressure sensing and FSK signal modulation functions, so that the circuit can be used as the pressure sensing component 31. At this time, the pressure sensing component 31 is not an independent chip, but a pressure sensing circuit as a whole constructed by the above-mentioned electronic components. The following still takes the pressure sensing component 31 as a pressure sensor chip as an example for explanation.

[0082] Among them, L3 and C1 form a series resonant network for filtering high-order harmonics. When the quality factor of the resonant network is high enough, the current flowing through the network is an ideal sinusoidal signal. L2, L3, and C3 are part of the Class-E amplifier inside the chip. The value of C3 consists of two parts, one is the parasitic capacitance of the transistor inside the chip, and the other is the capacitance actually introduced by the circuit board. C3 will affect the efficiency of RF. In the implementation of the solution, it can be decided whether to weld C3 based on the overall situation of the circuit. For example, C3 can be not welded to improve RF efficiency. In addition, the π-type network composed of C1, L1, and C2 is used for impedance transformation between PA and helical antenna 1. Of course, other types of matching networks can also be used, such as L-type, T-type, etc.

[0083] In one embodiment, the helical antenna 1 may include a first pin 11 and a second pin 12, wherein the first pin 11 serves as an input end of the helical antenna 1, and the second pin 12 is suspended. Figure 2 and 8The antenna support 2 may be provided with an axial groove 23, and the printed circuit board 3 may be provided with a welding hole 33 at a position vertically corresponding to the axial groove 23. By providing the welding hole 33, the first pin 11 may pass through the welding hole 33 and be welded to the output end of the antenna matching circuit 32, thereby forming an electrical connection between the input end of the helical antenna 1 and the antenna matching circuit 32.

[0084] The battery pins 41 of the battery 4 are respectively connected to the corresponding power supply pins of the printed circuit board 3 so as to supply power to the printed circuit board 3. Figure 8 As shown, a pin through hole 34 may also be opened at a position corresponding to the battery pin 41 on the printed circuit board 3, so that the battery pin 41 can pass through the corresponding pin through hole 34 and be connected (such as welding, crimping, etc.) to the corresponding power supply pin of the printed circuit board 3, thereby facilitating the smooth progress of subsequent assembly steps.

[0085] In one embodiment, the battery 4 may be a button cell. In order to miniaturize the sensor as much as possible, a button cell of the smallest possible size may be used. Exemplarily, the specification model of the button cell may be BR1632 (where "16" indicates that the battery diameter is 16 mm, and "32" indicates that the battery thickness is 3.2 mm, the same below), CR1632, BR1620, CR1620, BR1225, CR1225, BR1220 or CR1220. Taking a button cell with a size parameter of "1225" as an example, compared with a traditional TPMS sensor, the radial outer diameter of the tire pressure sensor can be reduced by about 8 mm, and the weight can be reduced by about 1 / 3 or more, effectively realizing the miniaturization of the tire pressure sensor.

[0086] In one embodiment, the difference between the maximum diameter of the helical antenna 1 along the circumferential outer diameter and the diameter of the battery 4 may be no greater than a third threshold value, so as to reduce the volume of the helical antenna 1 and the required space. The third threshold value may be a preset fixed value, such as 1 mm, 0.5 mm, 0.2 mm, etc., and the present application does not limit this. It can be understood that by reasonably setting the third threshold value, it can be ensured that the maximum diameter of the helical antenna 1 along the circumferential outer diameter is suitable for the diameter of the battery 4 (i.e., equal to or slightly larger than the diameter of the battery 4), so as to ensure that the internal structure of the assembled tire pressure sensor is compact and reduce vibration and wear.

[0087] In one embodiment, the tire pressure sensor may further include a base 6 and a shell 7 mounted on the base 6, and the shell 7 may be made of a material such as plastic that has little effect on signal transmission. A sealed cavity is formed between the base 6 and the shell 7, and a pressure transmission hole 61 connected to the sealed cavity is provided on the base 6. The sensor assembly 9 is placed in the sealed cavity, and a gas channel connecting the pressure transmission hole 61 and the air hole 51 is formed in the sealed cavity. One end of the gas channel is inside the tire, and the other end is the air hole 51, and the pressure sensing hole 311 corresponds to the position of the air hole 51. It can be seen that the gas pressure inside the tire can be transmitted to the pressure sensing hole 311 through the gas channel, so that the sensing device in the pressure sensing element 31 can accurately sense the pressure.

[0088] In some exemplary embodiments, the installation and sealing of the base 6 and the shell 7 can adopt the following structure: a circle of steps 72 is formed on the shell 7, a flange 62 is formed at the opening of the base 6, which is deflected toward the center and used to press the step 72 to achieve the fixation of the base 6 and the shell 7, and a sealing ring 63 is arranged between the base 6 and the shell 7 to form the aforementioned sealed cavity. In other exemplary embodiments, the sealing ring 63 can be placed in the base 6, and the shell 7 can be inserted into the base 6. The flange 62 deflected toward the center is formed at the opening of the base 6 through a riveting process to press the step 72. In this way, on the one hand, the base 6 and the shell 7 can be fixed, and on the other hand, the pressure generated by the riveting can be transmitted to the sealing ring 63, causing it to deform to further improve the sealing effect.

[0089] In one embodiment, in view of the fact that the sensor assembly 9 which is not completely hollow is placed in the aforementioned sealed cavity, and the outer side wall and end face of the protective body 5 in the sensor assembly 9 are in contact with or closest to the shell 7, the aforementioned gas channel can be formed between the protective body 5 and the shell 7. Due to the special shapes of the protective body 5 and the shell 7, the gas channel is not linear but curved. Specifically, the aforementioned gas channel can be formed by connecting the first gas channel, the second gas channel, and the third gas channel in sequence. Among them, the first gas channel is formed between the end face of the protective body 5 facing the base 6 and the bottom face of the base 6; the second gas channel is formed between the outer side wall of the protective body 5 and the inner side wall of the shell 7; the third gas channel is formed between the end face of the protective body 5 away from the base 6 and the inner wall of the end of the shell 7.

[0090] Furthermore, the above three gas passages can be formed by respectively setting corresponding structures at appropriate positions on the shield 5 and the shell 7. For example, a plurality of protrusions 52 can be formed on the end surface of the shield 5 facing the base 6, and the protrusions 52 can form the first gas passage between the shield 5 and the bottom surface of the base 6. For another example, Figure 6 As shown, a plurality of grooves 71 may be formed on the inner wall of the shell 7, and the grooves 71 may form the second gas channel between the outer wall of the shield 5 and the inner wall of the shell 7. For another example, a notch 53 may be formed on the end surface of the shield 5 away from the base 6, and the notch 53 may form the third gas channel between the shield 5 and the inner wall of the end of the shell 7.

[0091] It should be noted that the above-mentioned corresponding structures for forming corresponding gas channels are only exemplary, and other methods can also be used in the implementation of the solution. For example, for the first gas channel, Figure 7 The number c in FIG. 1 shows only 5 protrusions, and any number of protrusions such as 3, 4, or 6 may be provided; for another example, for the second gas channel, a plurality of grooves or protrusions may be formed on the outer wall of the protective body 5 (at the same time, the inner wall of the shell 7 may be provided with grooves or protrusions, or may be a rough annular surface, etc.), and this method may also form the second gas channel between the outer wall of the protective body 5 and the inner wall of the shell 7. In addition, the corresponding structures (protrusions, grooves, notches, etc.) forming the first gas channel, the second gas channel, and the third gas channel may be provided selectively or all of them, and the present application does not limit this.

[0092] In one embodiment, the absolute value of the difference between the angle between the gas flow direction of the second gas channel and the gas flow direction of the first gas channel (hereinafter referred to as the first angle) and 90° may not be greater than the first threshold; and / or, the absolute value of the difference between the angle between the gas flow direction of the second gas channel and the gas flow direction of the third gas channel (hereinafter referred to as the second angle) and 90° may not be greater than the second threshold. It can be understood that since the surface of the tire in contact with the ground is constantly changing during the movement of the vehicle, the air pressure of the tire at the valve is not kept constant, but may fluctuate. The above-mentioned first angle is used to describe the angle that the path needs to change when the gas enters the second gas channel from the first gas channel, and the second angle is used to describe the angle that the path needs to change when the gas enters the second gas channel from the second gas channel. The closer the absolute value of the first angle and the absolute value of the second angle are to 90° (i.e., a right angle), the greater the turning amplitude of the gas, so that when the tire pressure changes greatly (the gas flow rate is large at this time), the smaller the disturbance of the pressure in the previous gas channel to the pressure in the next gas channel, and the smoother the pressure transmission process. Therefore, this solution utilizes the change in flow direction to provide a certain buffer for the gas in the process of entering the second gas channel from the first gas channel and entering the third gas channel from the second gas channel, thereby making the pressure more stable, which is reflected in the detection results of the tire pressure sensor more accurately, helping to avoid sudden changes in the detection results.

[0093] Of course, since there may be errors in the production and assembly process of the components (protective body 5 and shell 7), the first threshold and the second threshold can be reasonably set according to the actual situation of production and assembly accuracy, and the present application does not limit this. Preferably, the above-mentioned first threshold and the second threshold can be set to be relatively small (as close to 0° as possible), such as both set to 5°, 2°, 1°, etc., so as to achieve as much as possible: the gas flow direction of the first gas channel is perpendicular to the gas flow direction of the second gas channel, and the gas flow direction of the third gas channel is perpendicular to the gas flow direction of the second gas channel, so as to achieve a better buffering effect.

[0094] In one embodiment, a buffer recess 54 connected to the air hole 51 may be formed on the end surface of the protective body 5 away from the base 6 to buffer the gas entering the buffer recess through the third gas channel. After a certain buffer is achieved through the aforementioned gas channel, the gas enters the buffer recess 54 through the third gas channel, and the gas will impact the side wall of the buffer recess 54. Under the action of the side wall, the gas pressure is buffered, thereby avoiding direct impact on the air hole 51 and the pressure transmission through hole 61, so that the gas pressure in the pressure transmission through hole 61 is relatively stable, and the measurement of the pressure sensing element 31 is more accurate.

[0095] In one embodiment, the helical antenna 1 and the pressure sensing hole 311 on the pressure sensing element 31 are both facing the side away from the base 6. Through this directional layout, the shielding of the radio frequency signal emitted by the helical antenna 1 by the base 6 and the valve 8 can be minimized as much as possible, which helps the tire pressure sensor have better signal transmission stability and higher signal strength. Given that metal materials usually have a greater impact on radio frequency signals, this layout can achieve better signal enhancement effects when at least one of the base 6 and the valve 8 is made of metal.

[0096] In fact, because the pressure sensing element 31 printed (i.e., welded) on the printed circuit board 3 has a certain thickness, and the structure of the battery 4 (usually a button battery) is fixed and cannot be opened, in order to ensure that the components are closely connected and save space as much as possible, the battery is placed on the back side of the printed circuit board 3 (i.e., the side relatively closer to the base 6). In addition, because the helical antenna 1 of the present solution faces the side away from the base 6 (i.e., the side where the helical antenna 1 is farther away from the base 6 than the battery 4, and the helical antenna 1 and the battery 4 are respectively located on both sides of the printed circuit board 3), and the printed circuit board 3 and the battery 4 are not hollow (wherein, it is difficult to open a hole in the printed circuit board 3 because it may affect the layout of the components in the circuit, etc.; and it is even more impossible to open a hole in the already formed battery 4, and since the battery 4 cannot be replaced, replacing the battery 4 with a smaller size will reduce the overall life of the tire pressure sensor), it is impossible to directly conduct gas pressure through a linear gas channel formed by a hollow component like a traditional TPMS sensor (the antenna in this type of sensor is closer to the base than the circuit board). Because of this, the present solution sets up a gas passage (composed of multiple connected sections) from the pressure transmission through hole 61 to the pressure sensing hole 311 in the aforementioned manner so as to transmit the pressure inside the tire to the pressure sensing hole 311 on the pressure sensing element 31 (the hole is located in a direction away from the base 6).

[0097] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the disclosure disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0098] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

[0099] It should be noted that, in this application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0100] The method and device provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of the present application should not be understood as a limitation on the present application.

Claims

1. A tire pressure sensor, characterized in that: include: A sensor assembly (9) is obtained by injection molding a printed circuit board (3), a battery (4) and a helical antenna assembly (10), wherein: The battery pins (41) of the battery (4) are respectively connected to the corresponding power supply pins of the printed circuit board (3); the helical antenna assembly (10) comprises an antenna bracket (2) and a helical antenna (1) arranged on the outer wall of the antenna bracket (2); the antenna bracket (2) is hollow inside, the outer wall of the antenna bracket (2) is provided with a helical groove (22), the helical antenna (1) is wound in the helical groove (22), and the bottom of the antenna bracket (2) is provided with a plurality of buckles (21) for fixing the circuit board; The printed circuit board (3) is printed with a pressure sensing component (31) and an antenna matching circuit (32), and the antenna matching circuit (32) is used to transmit the radio frequency signal output after the pressure sensing component (31) modulates the sensed tire pressure signal to the input end of the helical antenna (1).

2. The tire pressure sensor according to claim 1, characterized in that: The injection molding process forms a protective body (5) covering the printed circuit board (3), the battery (4) and the helical antenna assembly (10), and an air hole (51) is provided on the protective body (5) at a position corresponding to the pressure sensing hole (311) of the pressure sensing element (31).

3. The tire pressure sensor according to claim 2, characterized in that: The invention also comprises a base (6) and a shell (7) mounted on the base (6); a sealed cavity for accommodating the sensor assembly (9) is formed between the base (6) and the shell (7); a pressure transmission through hole (61) communicating with the sealed cavity is formed on the base (6); a gas channel communicating with the pressure transmission through hole (61) and the air hole (51) is formed in the sealed cavity.

4. The tire pressure sensor according to claim 3, characterized in that: The gas channel is formed by sequentially connecting the first gas channel, the second gas channel, and the third gas channel, wherein: The first gas channel is formed between the end surface of the protective body (5) facing the base (6) and the bottom surface of the base (6); The second gas channel is formed between the outer wall of the protective body (5) and the inner wall of the shell (7); The third gas channel is formed between the end surface of the protective body (5) away from the base (6) and the inner wall of the end of the shell (7).

5. The tire pressure sensor according to claim 4, characterized in that: A plurality of protrusions (52) are formed on the end surface of the protective body (5) facing the base (6), and the protrusions (52) form the first gas channel between the protective body (5) and the bottom surface of the base (6); A plurality of grooves (71) are formed on the inner wall of the shell (7), and the grooves (71) form the second gas channel between the outer wall of the protective body (5) and the inner wall of the shell (7); and / or, A notch (53) is formed on the end surface of the protective body (5) away from the base (6), and the notch (53) forms the third gas channel between the protective body (5) and the inner wall of the end of the shell (7).

6. The tire pressure sensor according to claim 4, characterized in that: The absolute value of the difference between the angle between the gas flow directions of the second gas channel and the first gas channel and 90° is not greater than a first threshold; and / or, An absolute value of a difference between an angle between gas flow directions of the second gas channel and the third gas channel and 90° is not greater than a second threshold.

7. The tire pressure sensor according to claim 3, characterized in that: A buffer recessed portion (54) communicating with the air hole (51) is also formed on the end surface of the protective body (5) away from the base (6).

8. The tire pressure sensor according to claim 3, characterized in that: The helical antenna (1) and the pressure sensing hole (311) on the pressure sensing element (31) are both oriented toward a side away from the base (6).

9. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The printed circuit board (3), the battery (4) and the helical antenna assembly (10) are integrally formed by an injection molding process to obtain the sensor assembly (9); or, The printed circuit board (3), the battery (4) and the helical antenna assembly (10) are formed into a plurality of injection-molded parts through an injection molding process, and the plurality of injection-molded parts are assembled into the sensor assembly (9).

10. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The injection molding process is a low-pressure injection molding process.

11. The tire pressure sensor according to claim 10, characterized in that: The injection molding material of the low-pressure injection molding process is thermoplastic polyamide.

12. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The pressure sensing element (31) is a sensor chip integrated with a pressure sensing device.

13. The tire pressure sensor according to claim 12, characterized in that: The sensor chip is also integrated with a temperature sensing device, an acceleration sensing device and / or an angle sensing device.

14. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The radio frequency signal outputted by the pressure sensing element (31) after modulating the sensed tire pressure signal includes: The tire pressure signal is subjected to frequency shift keying (FSK) modulation to output an FSK signal; or, The tire pressure signal is modulated by amplitude shift keying (ASK) to output an ASK signal.

15. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The helical antenna (1) comprises a first pin (11) and a second pin (12), wherein the first pin (11) serves as an input end of the helical antenna (1), and the second pin (12) is suspended, wherein: The antenna bracket (2) is provided with an axial groove (23), a welding hole (33) is provided on the printed circuit board (3) at a position vertically corresponding to the axial groove (23), and the first pin (11) passes through the welding hole (33) and is welded to the output end of the antenna matching circuit (32).

16. The tire pressure sensor according to any one of claims 1 to 8, characterized in that: The battery (4) is a button battery, and its specifications are BR1632, CR1632, BR1620, CR1620, BR1225, CR1225, BR1220 or CR1220.

17. A valve, characterized in that: The tire pressure sensor according to any one of claims 1 to 16 is mounted on the valve stem.

Images