JP2005055319A - System for monitoring air pressure of tire of car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system of a simple constitution for monitoring the air pressure of tires of a car capable of easily improving reception performance on the side of a reception unit in the car's cabin. <P>SOLUTION: In the system for monitoring the air pressure of tires of a car equipped with both a transmitter for detecting the air pressure of a tire of each wheel outside the car's cabin and transmitting detection signals via radio waves and a reception unit for receiving the detection signals from the transmitter inside the car's cabin, a sensor member mounted to a member on the side of a vehicle body located in the vicinity of the wheels for detecting the state of the wheels and connected via a harness member to a control unit for controlling the car on the basis of signals from the outside is constituted as an aerial for receiving radio signals from the transmitter. The aerial is constituted by winding the aerial on the harness member in a coil shape in the vicinity of the sensor member. The aerial may be constituted by incorporating an aerial line for receiving the radio signals from the transmitter inside the main body of the sensor member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle tire pressure monitoring system.

  Conventionally, a tire pressure monitoring system (TPMS: Tire Pressure Monitoring System) that warns the driver's seat when excessive or insufficient air pressure or temperature abnormality occurs in a running wheel tire is known as one of vehicle safety measures. (For example, refer to Patent Document 1). In this system, basically, a transmitter incorporating a sensor for detecting tire air pressure and temperature is attached to each wheel, and a receiving unit for receiving a radio signal from the transmitter in a passenger compartment. Is installed. The information signal indicating the pressure and temperature of the tire detected by the sensor is transmitted by radio waves from the transmitter, received by the receiving unit via the antenna element, and then the state of the pressure and temperature acquired based on the signal information The driver's seat is notified accordingly.

JP 2000-182164 A

  However, in the tire pressure monitoring system described above, a metal underbody (mainly a floor panel) interposed between a transmitter attached to each wheel outside the passenger compartment and a receiving unit installed in the passenger compartment is always a radio wave. There is a possibility that the radio wave transmitted from the transmitter to the receiving unit is obstructed, and it has been difficult to constantly acquire signals from all transmitters.

  The present invention provides a vehicle tire pressure monitoring system that can easily and simply receive a radio signal from a transmitter provided in each tire on the receiving unit side and improve reception performance with a simple structure. The purpose is to provide.

  The invention according to claim 1 of the present application includes a transmitter that detects the tire air pressure of each wheel outside the passenger compartment and transmits a detection signal by radio waves, and a receiving unit that receives the detection signal from the transmitter in the passenger compartment. A tire pressure monitoring system for a vehicle equipped with a sensor member that is attached to a vehicle body side member located in the vicinity of the wheel and detects a state of the wheel, and a control unit that controls the vehicle based on an external signal; The sensor member connected via the harness member is configured as an antenna that receives radio waves from the transmitter.

  The invention according to claim 2 of the present application is characterized in that, in claim 1, the antenna is configured to be wound around the harness member in a coil shape in the vicinity of the sensor member. .

  Furthermore, in the invention according to claim 3 of the present application, in claim 1, the antenna is configured such that an antenna wire for receiving a radio wave signal from the transmitter is incorporated in the main body of the sensor member. It is characterized by.

  Furthermore, the invention according to claim 4 of the present application is characterized in that, in any one of the inventions according to claims 1 to 3, the sensor member is a wheel speed sensor.

  According to the invention of claim 1 of the present application, an antenna can be disposed in the vicinity of the transmitter attached to the wheel, and good reception performance can be easily ensured. Further, since an antenna is provided for each transmitter, the tire state can be individually determined, and the tire pressure can be detected more strictly.

  Further, according to the invention according to claim 2 of the present application, it is not necessary to secure a new location for the antenna that receives the signal from the transmitter, and the component mounting structure is simplified. Thus, cost reduction can be realized.

  Furthermore, according to the invention according to claim 3 of the present application, it is not necessary to secure a new location for the antenna that receives the signal from the transmitter, and the component mounting structure is simplified. Thus, cost reduction can be realized.

  Further, according to the invention according to claim 4 of the present application, the wheel speed sensor disposed in the vicinity of the wheel is configured as an antenna, so that the reception performance on the receiving unit side is easily improved with a simple structure. Can be made.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing the configuration of a tire pressure monitoring system and an antilock brake system mounted on a vehicle according to one embodiment of the present invention. In this vehicle 1, as a tire pressure monitoring system (hereinafter referred to as TPMS), the pressure of each tire 44 (see FIG. 2) is detected by each wheel 2A, 2B, 2C, 2D and converted into an electrical signal. Wheel units 3A, 3B, 3C, and 3D each including a sensor 4 and a transmitter 6 that wirelessly transmits a signal output from the air pressure sensor 4 are attached. Each wheel unit 3A, 3B, 3C, 3D is attached to the tire wheel 43 of the wheels 2A, 2B, 2C, 2D, and can rotate as the wheel 2 rotates. The wheels 2A, 2B, 2C, and 2D are front left, front right, rear left, and rear right wheels, respectively.

  On the other hand, a receiving unit 10 to which a signal transmitted from a transmitter 6 incorporated in the wheel units 3A, 3B, 3C, 3D is supplied is mounted in the vehicle interior. As will be described in detail later, the receiving unit 10 receives signals transmitted from the transmitters 6 via the antenna elements 7A, 7B, 7C, and 7D connected to the unit main body. The receiving unit 11 includes a predetermined signal processing circuit (not shown), performs calculation and control based on the received signal, and generates a signal for notification on the display 12 located in front of the driver's seat.

  Further, in the vehicle 1, gear-shaped sensor rotors 21 </ b> A, 21 </ b> B, 21 </ b> C, 21 </ b> D are provided inside the wheels 2 </ b> A, 2 </ b> B, 2 </ b> C, 2 </ b> D, respectively, as a configuration of an anti-lock brake system (hereinafter referred to as ABS). Yes. Each of the sensor rotors 21A, 21B, 21C, and 21D is attached to a vehicle body side member (not shown) such as an axle flange to which the wheel body is fastened and fixed, and can be rotated as the wheel rotates. Furthermore, wheel speed sensors 22A, 22B, 22C, and 22D are provided inside the wheels 2A, 2B, 2C, and 2D and in the vicinity of the sensor rotors 21A, 21B, 21C, and 21D. Each wheel speed sensor 22A, 22B, 22C, 22D is attached to a vehicle body side member (for example, a steering knuckle on the front side and a toe control hub outer on the rear side) fixed near the wheel and near the sensor rotor. .

  The wheel speed sensors 22A, 22B, 22C, 22D detect the rotational speed of the wheels based on the rotational operation of the sensor rotors 21A, 21B, 21C, 21D and convert them into electrical signals. A bias magnet that generates a bias magnetic field toward the sensor rotors 21A, 21B, 21C, and 21D provided inside 2B, 2C, and 2D is provided, and a bias that is generated as the sensor rotors 21A, 21B, 21C, and 21D rotate. The wheel speed is detected by detecting the change in the magnetic field with the magnetoelectric transducer.

  On the other hand, an ABS hydraulic unit (hereinafter referred to as an ABS unit) 20 is mounted in the passenger compartment for receiving braking signals in response to signals output from the wheel speed sensors 22A, 22B, 22C, and 22D. The wheel speed sensors 22A, 22B, 22C, and 22D are connected to the ABS unit 20 via harness cables 23A, 23B, 23C, and 23D, respectively.

  In FIG. 2, in the TPMS, signals from the transmitter 6 incorporated in the wheel units 3A, 3B, 3C, 3D are received by the antenna elements 7A, 7B, 7C, 7D connected to the receiving unit 10 in the vehicle interior. It is explanatory drawing which shows a mode. In the following description, the front left wheel 2A and the related configuration are taken as an example, but the same configuration and functions are set for the other wheels 2B, 2C, and 2D. Description is omitted. As shown in FIG. 2, the wheel unit 3 </ b> A is configured such that the air pressure sensor 4, the acceleration sensor 5, and the transmitter 6 are housed in a case 42 that is formed integrally with an air valve 41 for introducing air into the tire 44. ing. The wheel unit 3 </ b> A is fixed to the tire wheel 43 by, for example, screwing the air valve 41 with a nut (not shown).

  A signal representing the air pressure of the tire 44 and the acceleration of the wheel 2 </ b> A detected by the air pressure sensor 4 or the acceleration sensor 5 is transmitted as a radio wave W from the transmitter 6 and received by the antenna element 7 </ b> A connected to the receiving unit 10. , And supplied to the receiving unit 10. The antenna element 7A is connected to the receiving unit 10 via a signal transmission line 8A. Further, the receiving unit 10 is connected to a display device 12 disposed in front of the driver's seat via a controller area network (CAN) 13. This indicator 12 is provided with a warning lamp 12a, which is turned on when the tire air pressure drops below a predetermined value.

  In the present embodiment, in the TPMS, antenna elements 7A, 7B, 7C, 7D connected to the receiving unit 10 are respectively in the wheel units 3A, 3B, 3C, 3D attached to the wheels 2A, 2B, 2C, 2D. The transmitter 6 is disposed in the vicinity of the transmitter 6. Hereinafter, a method for arranging the antenna elements will be described with reference to FIGS.

  First, FIG. 3 shows a first example of a method for arranging antenna elements. As described above, as the ABS configuration, the wheel speed sensor 22A is provided in the vicinity of the sensor rotor 21A (see FIG. 1) provided inside the wheel 2A, and the wheel speed sensor 22A and the ABS unit 20 are connected to each other. A harness cable 23A for signal transmission is provided between them. In this example, the antenna element 7A of TPMS is configured to be wound around the harness cable 23A in a coil shape in the vicinity of the wheel speed sensor 22A. A signal received by the antenna element 7A is supplied to the receiving unit 10 via a signal transmission line 8A connected to the antenna element 7A.

  According to such an arrangement method, the antenna element 7A can be positioned in the vicinity of the transmitter 6 in the wheel unit 3A attached to the wheel 2A, and better reception performance can be ensured. In this case, since the TPMS antenna is configured around the harness cable 23 that is the ABS configuration, it is not necessary to secure a new installation place for the antenna that receives the signal from the transmitter 6. Moreover, cost reduction can be realized by simplifying the component mounting structure.

  FIG. 4 shows a second example of a method for arranging antenna elements. In this example, the antenna element 7A of the TPMS is specifically incorporated into the wheel speed sensor 22A with respect to the main body of the wheel speed sensor 22A so as to form a coil shape. A signal transmission line 8A for guiding a signal received from the antenna element 7A to the receiving unit 10 is bundled together with a harness cable 23A for the wheel speed sensor 22A. Although not particularly illustrated, the signal transmission line 8A and the harness cable 23A are branched in the middle and connected to the receiving unit 10 and the ABS unit 20, respectively.

  According to such an arrangement method, the antenna element 7A can be positioned in the vicinity of the transmitter 6 in the wheel unit 3A attached to the wheel 2A, and better reception performance can be ensured. In this case, since the TPMS antenna is configured with respect to the main body of the wheel speed sensor 22A which is an ABS configuration, it is not necessary to secure a new location for the antenna that receives the signal from the transmitter 6. Moreover, cost reduction can be realized by simplifying the component mounting structure.

  By adopting the first and second examples of the arrangement method, an antenna element is provided in the vicinity of the transmitter 6 in the wheel units 3A, 3B, 3C, 3D attached to the wheels 2A, 2B, 2C, 2D. 7A, 7B, 7C, and 7D can be provided, and reception performance can be easily improved. Further, when a dedicated antenna element is provided for the transmitter 6 provided on each wheel as in the present embodiment, the antenna elements 7A, 7B, 7C, and 7D separately transmit signals from the transmitter 6. Therefore, the state of the tires 2A, 2B, 2C, 2D can be individually determined. For example, when the air pressure of any one of the four tires is reduced, It is possible to identify the tire. That is, the tire pressure can be detected more strictly.

  It should be noted that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the scope of the present invention.

1 is a diagram schematically showing a tire pressure monitoring system and an anti-lock brake system configured in a vehicle according to an embodiment of the present invention. In the said tire pressure monitoring system, it is explanatory drawing which shows a mode that the signal from the transmitter integrated in the wheel unit is received with the antenna element connected to the receiving unit in a vehicle interior. It is a figure which shows the 1st example of the arrangement | positioning method of the said antenna element. It is a figure which shows the 2nd example of the arrangement | positioning method of the said antenna element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle 2A, 2B, 2C, 2D ... Wheel 3A, 3B, 3C, 3D ... Wheel unit 4 ... Air pressure sensor 6 ... Transmitter 7A, 7B, 7C, 7D ... Antenna element 8A, 8B, 8C, 8D ... Signal transmission Wire 10 ... Receiving unit 12 ... Display device 20 ... ABS unit 21A ... Sensor rotor 22A, 22B, 22C, 22D ... Wheel speed sensor 23A, 23B, 23C, 23D ... Harness cable 43 ... Tire wheel 44 ... Tire

Claims (4)

Tire pressure monitoring of a vehicle equipped with a transmitter that detects the tire air pressure of each wheel outside the cabin and transmits a detection signal by radio wave, and a receiving unit that receives the detection signal from the transmitter inside the cabin In the system,
A sensor member attached to a vehicle body side member located in the vicinity of the wheel for detecting the state of the wheel, the sensor member connected via a harness member and a control unit for controlling the vehicle based on a signal from the outside, A tire pressure monitoring system configured as an antenna for receiving radio waves from a transmitter.   The tire pressure monitoring system according to claim 1, wherein the antenna is configured to be wound around the harness member in a coil shape in the vicinity of the sensor member.   2. The tire pressure monitoring system according to claim 1, wherein the antenna is configured such that an antenna wire for receiving a radio signal from the transmitter is incorporated in a main body of the sensor member. The tire pressure monitoring system according to any one of claims 1 to 3, wherein the sensor member is a wheel speed sensor.

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