JP2012030724A - Sensor unit and sensor unit registration method of tire air pressure monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor unit capable of improving convenience upon switching operation modes.SOLUTION: In this sensor unit U1, a valve part 30 which is an air injection port of a tire, a sensor part 20 that detects the air pressure of the tire, and a transmission antenna that transmits a detection signal including air pressure information of the tire detected through the sensor part are made integral. A cap 31 is made to have electric resistance and a resistance detection circuit that detects the electric resistance is provided. The operation modes of the sensor unit U1 are changed based on the electric resistance detected through the resistance detection circuit.

Description

  The present invention relates to a sensor unit for detecting tire air pressure, and a sensor unit registration method of a tire air pressure monitoring system using the sensor unit.

  As this type of tire pressure monitoring system (TPMS: Tire Pressure Monitoring System), for example, a system described in Patent Document 1 is known. In the tire air pressure monitoring system described in Patent Document 1, a sensor unit that detects a tire air pressure and transmits a detection signal including information on the detected tire air pressure is provided on each wheel of the vehicle. Incidentally, a unique identification code is set for each wheel sensor unit, and each wheel sensor unit transmits its own identification code when transmitting a detection signal. And after the detection signal transmitted from the sensor unit is received by the receiver provided in the vehicle, it is transmitted to the control device also provided in the vehicle. This control device has a nonvolatile memory and the like, and is a part that performs overall control of the tire pressure monitoring system. In the memory, for example, registration information indicating the relationship between the identification code of the sensor unit and the position of each wheel is stored. In this control device, when the detection signal is received, the tire included in the detection signal is compared with the identification code included in the detection signal and the registration information stored in the memory. It is determined which of the wheels has the air pressure information. In addition, the control device monitors the tire air pressure of each wheel based on such a determination method, and if an abnormality is detected in the tire air pressure of any wheel, the wheel in which the abnormality is detected is specified. A warning is displayed so that it can be done.

  According to such a configuration as the tire pressure monitoring system, the driver can know which of the wheels has an abnormality by a warning display, so that a quick and accurate countermeasure can be taken for the wheel in which the abnormality has occurred. Can be applied. For this reason, it becomes possible to ensure the safety of the vehicle accurately.

JP 2006-327539 A

  Incidentally, a battery is usually built in the sensor unit, and an operating power source of the sensor unit is often secured by this battery. However, in a sensor unit using a battery as an operating power supply, for example, if transmission of a detection signal is repeated from the time of manufacture until it is actually used, the battery may be consumed and the life of the sensor unit may be shortened.

  For this reason, in such a sensor unit, generally, at the time of manufacture, it is set to a stop mode in which detection signals are not transmitted, and on condition that a start signal transmitted from a dedicated tool (device) is received. The mode is shifted to the normal mode in which the detection signal is transmitted. According to such a configuration, since the stop mode is set at the time of manufacture, the sensor unit does not repeat transmission of the detection signal. Therefore, the above-described battery consumption can be accurately suppressed. Further, when starting use of the sensor unit, for example, if a dealer operates a dedicated tool and transmits an activation signal to the sensor unit, transmission of a detection signal is started from that point. Therefore, the function required as a sensor unit can also be satisfied.

  However, in such a configuration, a dedicated tool is indispensable when the sensor unit is switched from the stop mode to the normal mode, and this is one factor that deteriorates the convenience of the dealer.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a sensor unit that can improve convenience when switching operation modes, and a sensor unit registration method for a tire pressure monitoring system. It is in.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a valve portion serving as an air inlet of a tire, a sensor portion for detecting the air pressure of the tire, and a tire pressure detected through the sensor portion. In a sensor unit integrated with a transmission antenna that wirelessly transmits a detection signal including information, a mounting member that is detachably mounted on the valve unit, and detection that detects electrical characteristics or magnetic characteristics of the mounting member And changing the operation mode when transmitting the detection signal from the transmission antenna based on the electrical characteristics or magnetic characteristics of the mounting member detected through the detection section.

  According to this configuration, the operation mode of the sensor unit can be changed simply by mounting mounting members having different electrical characteristics or magnetic characteristics on the valve portion. Thereby, since the operation mode of the sensor unit can be changed without using the dedicated tool described above, the operation mode of the sensor unit can be easily changed as compared with the conventional case. Therefore, the convenience of the dealer is improved.

And in this case, as in the invention according to claim 2,
The mounting member has a predetermined impedance as the electrical characteristic, and the detection unit detects the impedance of the mounting member.
Or according to the invention according to claim 4,
The mounting member has a predetermined magnetic permeability as the magnetic characteristic, and the detection unit detects the magnetic permeability of the mounting member.
It is effective to adopt such a configuration. According to these configurations, the mounting member having electrical characteristics or magnetic characteristics can be easily manufactured, so that the invention according to claim 1 can be easily realized.

  According to a third aspect of the present invention, in the sensor unit according to the second aspect, the mounting member has a predetermined electric resistance as the impedance, and the detection unit detects an electric resistance of the mounting member. The gist is to do.

  If the mounting member has a predetermined electrical resistance as in the same configuration, the structure can be simplified and the cost can be reduced while the mounting member has electrical characteristics. .

  According to a fifth aspect of the present invention, in the sensor unit according to the fourth aspect, the mounting member is provided with a yoke having a predetermined magnetic permeability, and the magnetic permeability of the mounting member is determined based on the magnetic permeability of the yoke. Is set as the gist.

According to this configuration, the magnetic permeability of the mounting member can be changed simply by changing the magnetic permeability of the yoke, so that the magnetic characteristics of the mounting member can be set easily and accurately.
According to a sixth aspect of the present invention, in the sensor unit according to any one of the first to fifth aspects, the detection signal is transmitted in an operation mode when the detection signal is transmitted from the transmission antenna. The gist is that a normal mode and a stop mode for stopping transmission of the detection signal are included.

  As described above, according to the present invention, it is effective to adopt the normal mode for transmitting the detection signal and the stop mode for stopping the transmission of the detection signal as the operation mode when transmitting the detection signal from the transmission antenna. As a result, if the operation mode of the sensor unit is set to the stop mode during manufacture and the operation mode of the sensor unit is set to the normal mode during actual use, the sensor unit is built in while satisfying the functions required for the sensor unit. It is possible to accurately suppress the consumption of the battery. Therefore, the lifetime of the sensor unit can be improved.

  According to a seventh aspect of the present invention, in the sensor unit according to the sixth aspect, the detection signal includes an identification code unique to the sensor unit and a registration signal including the identification code as the operation mode. A registration mode for wireless transmission from the transmission antenna is further included, and when the operation mode is set to the normal mode, the detection signal is intermittently transmitted in a first period, and the operation mode is the registration mode. When the mode is set, the gist is that the registration signal is intermittently transmitted in a second period shorter than the first period.

  In the tire pressure monitoring system using such a sensor unit, as described above, a sensor unit is provided on each wheel of the vehicle. And when transmitting a detection signal from a sensor unit, the identification code peculiar to a sensor unit is included in the detection signal and transmitted, so that the tire air pressure of each wheel is monitored separately. In addition, when it is going to monitor the tire air pressure of each wheel separately in this way, it is necessary to perform a registration operation for registering the relationship between the identification code of the sensor unit and the position of each wheel. By the way, in such a tire pressure monitoring system, the cycle for transmitting the detection signal intermittently is usually set to a relatively long cycle such as “1 minute” in addition to the cycle for detecting the tire pressure. Often done. Therefore, if the detection signal is used when performing the above-described registration work, it is necessary to wait for a period until the detection signal is transmitted from the sensor unit, that is, a transmission cycle period at the longest. May take time. In this regard, according to the above configuration, when the sensor unit is set to the registration mode, the registration signal including the identification code is intermittently transmitted at a cycle shorter than the transmission cycle of the detection signal. If the registration work is performed, the time required for the registration work can be shortened. Therefore, the work efficiency is improved.

  The invention according to claim 8 is provided at each wheel of the vehicle by exchanging the detection signal between the sensor unit according to any one of claims 1 to 6 and an in-vehicle device provided in the vehicle. When the tire pressure is monitored separately, the sensor unit is provided separately for each wheel, and includes a unique identification code in the detection signal when transmitting the detection signal. The on-vehicle device has storage means for storing registration information indicating the relationship between the identification code and the position of each wheel, and is included in the detection signal when the detection signal is received. Based on the identification code and the registration information, it is determined which of the wheels the tire pressure information included in the detection signal is, and based on the determination result of each wheel In the tire pressure monitoring system for separately monitoring the air pressure of the ear, the sensor unit registration method for registering the identification code of the sensor unit in the storage means as the registration information in association with the position of each wheel, The sensor unit transmits the detection signal when it is determined that the electrical property or magnetic property of the mounting member detected through the detection unit is a specific electrical property or magnetic property, The in-vehicle device transmits the detection signal transmitted from the sensor unit of each wheel when the mounting member exhibiting the specific electrical characteristic or magnetic characteristic is mounted on the valve portion of each wheel in a predetermined order. When received, the identification code included in the detection signal is associated with the position of each wheel in the predetermined order. Are summarized as to register in the storage means a record as the registration information.

  According to a ninth aspect of the present invention, the air pressures of the tires provided on the respective wheels of the vehicle are transferred by transmitting and receiving the detection signal between the sensor unit according to the seventh aspect and the in-vehicle device provided in the vehicle. In the separate monitoring, the sensor unit is provided separately for each wheel, and when transmitting the detection signal, the sensor unit includes a unique identification code in the detection signal. And a storage means for storing registration information indicating a relationship between the identification code and the position of each wheel, and when the detection signal is received, the identification code included in the detection signal and the registration And determining which of the wheels the tire pressure information included in the detection signal is based on the information, and determining the tire air of each wheel based on the determination result A sensor unit registration method for registering the identification code of the sensor unit in the storage means as the registration information in association with the position of each wheel. The registration signal is transmitted when it is determined that the electrical property or magnetic property of the mounting member detected through the detection unit is a specific electrical property or magnetic property, and the specific signal is transmitted. When the vehicle-mounted device receives the registration signal transmitted from the sensor unit of each wheel when the mounting member exhibiting electrical characteristics or magnetic characteristics is mounted on the valve portion of each wheel in a predetermined order. The identification code included in the registration signal is associated with the position of each wheel in the predetermined order and is registered as the registration code. Are summarized as to register in the storage means as the information.

  As the tire pressure monitoring system, the above-described configuration, that is, a configuration in which an identification code is set for each sensor unit and registration information indicating the relationship between the identification code and the position of each wheel is stored in the storage unit of the in-vehicle device. By adopting it, the tire pressure of each wheel can be monitored separately. However, the tire mounting position of each wheel may be changed by, for example, tire rotation performed at the time of vehicle inspection. In such a case, the sensor unit identification code provided on each wheel and the wheel The relationship with the position needs to be registered again in the registration information. In this regard, according to the above method, the identification code of the sensor unit is assigned to the position of each wheel only by mounting the mounting member exhibiting specific electrical characteristics or magnetic characteristics on the valve portion of each wheel in a predetermined order. Since registration can be performed in association with each other, registration work can be easily performed.

  According to the sensor unit and the tire unit monitoring method of the tire pressure monitoring system according to the present invention, it is possible to improve convenience when switching the operation mode.

The block diagram which shows the system configuration | structure of the tire pressure monitoring system using the sensor unit about 1st Embodiment of the sensor unit concerning this invention. The table | surface which shows the content of the registration information memorize | stored in memory of the vehicle side control apparatus. Sectional drawing which shows the cross-section of the right front wheel of a vehicle. The perspective view which shows the disassembled perspective structure about the sensor unit of the 1st Embodiment. (A), (b) is sectional drawing which each shows the cross-sectional structure along the AA line of FIG. 4, and the cross-sectional structure along the BB line. The circuit diagram which shows the structure of the resistance detection circuit about the sensor unit of the said 1st Embodiment. The circuit diagram which shows the structure of the resistance detection circuit about the sensor unit of the said 1st Embodiment. The chart which shows the relationship between the kind of the cap, and electrical resistance about the sensor unit of the said 1st Embodiment. The block diagram which shows the system configuration | structure about the sensor unit of the 1st Embodiment. The chart which shows the relationship between the electrical resistance detected through a resistance detection circuit, and an operation mode about the sensor unit of the said 1st Embodiment. (A), (b) compares the signal transmitted from the sensor unit when the normal mode is set with the signal transmitted from the sensor unit when the registration mode is set. Time chart shown. The flowchart which shows the process sequence about the registration information update process by a tire pressure monitoring system. The chart which shows the relationship between the value of "N" and the position of a wheel. The figure which shows typically the operation example of a tire pressure monitoring system. (A)-(d) is a chart which shows a mode that registration information is updated. The circuit diagram which shows the structure of the magnetic permeability detection circuit about 2nd Embodiment of the sensor unit concerning this invention. The circuit diagram which shows the structure of the magnetic permeability detection circuit about the sensor unit of the said 2nd Embodiment. The chart which shows the relationship between the kind of the cap and the magnetic permeability of a yoke about the sensor unit of the said 2nd Embodiment. The chart which shows the relationship between the magnetic permeability of a yoke, and an operation mode about the sensor unit of the said 2nd Embodiment. The flowchart which shows the process sequence about the registration information update process by a tire pressure monitoring system.

<First Embodiment>
A sensor unit according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing a system configuration of a tire pressure monitoring system using a sensor unit according to the present embodiment. First, an overview of the tire pressure monitoring system will be described with reference to FIG. To do. In FIG. 1, the right front wheel is indicated by W1, the left front wheel is indicated by W2, the right rear wheel is indicated by W3, and the left rear wheel is indicated by W4.

  As shown in FIG. 1, the tire air pressure monitoring system is mainly composed of sensor units U1 to U4 provided on the wheels W1 to W4, respectively, and an in-vehicle device 10 provided on the vehicle. Here, the sensor units U1 to U4 detect the air pressure of the tire and send a detection signal including information on the detected tire air pressure and unique identification codes (ID codes) ID1 to ID4 in a first period T1 (for example, "1 minute")) and wireless transmission intermittently. And the detection signal transmitted from each sensor unit U1-U4 is received by the receiver 11 provided in a vehicle, and is similarly transmitted to the vehicle side control apparatus 12 provided in a vehicle. The vehicle-side control device 12 includes a nonvolatile memory 12a as a storage unit and the like, and is a part that performs overall control of the tire pressure monitoring system. As shown in FIG. 2, the memory 12a stores registration information indicating the relationship between the positions of the wheels W1 to W4 and the identification codes ID1 to ID4 of the sensor units U1 to U4. Then, the vehicle-side control device 12 compares the identification code included in the detection signal transmitted from the receiver 11 with the registration information, so that the tire pressure information included in the detection signal is It is determined which of the wheels W1 to W4 is. Further, the vehicle-side control device 12 monitors the tire air pressure of each of the wheels W1 to W4 based on such a determination method, and when an abnormality is detected in the tire air pressure of any wheel, for example, the vehicle A warning is given so that the wheel in which the abnormality is detected can be identified by turning on the indicator 13 provided on the instrument panel. Incidentally, the vehicle-side control device 12 performs processing for registering the identification code in the registration information when the sensor unit mounted on each of the wheels W1 to W4 is changed due to, for example, tire replacement or the like. The process of blinking the turn signal lamp 14 is also executed to notify the user of the fact when the user is registered. Moreover, in this embodiment, the vehicle-mounted apparatus 10 is comprised by the receiver 11, the vehicle side control apparatus 12, the indicator 13, the turn signal lamp 14, etc. FIG.

  Next, the structure of the sensor unit U1 will be described in detail with reference to FIGS. FIG. 3 shows a cross-sectional structure of the right front wheel W1, and FIG. 4 shows an exploded perspective structure of the sensor unit U1. 5A shows a cross-sectional structure along the line AA in FIG. 4, and FIG. 5B shows a cross-sectional structure along the line BB in FIG. is there. Since the sensor units U1 to U4 have the same structure, only the structure of the sensor unit U1 will be described below as a representative for convenience.

  As shown in FIG. 4, the sensor unit U1 is roughly composed of a sensor unit 20 in which various electronic components such as a pneumatic sensor and a transmission antenna are integrated, and an air inlet port attached to the sensor unit 20. It is comprised from the cylindrical valve part 30 which functions as. As shown in FIG. 3, the former sensor unit 20 is disposed on the rim bottom 42 of the wheel 41 inside the tire 40, while the latter valve unit 30 penetrates the wheel 41 and externally. Has been derived.

  Here, as shown in FIG. 4, a threaded portion 30a made of an external thread is formed on the distal end side of the valve portion 30, and a bottomed cylindrical cap 31 is screwed to the threaded portion 30a. That is, the cap 31 is detachably attached to the valve unit 30. And by attaching the cap 31 to the valve part 30, the leakage of the air from the valve part 30 is suppressed. A threaded portion 30b made of an external thread is formed from the central portion to the base end portion of the valve portion 30, and a nut 32 is screwed onto the threaded portion 30b. That is, the nut 32 is also detachably attached to the valve unit 30. As shown in FIG. 3, the sensor unit U <b> 1 is attached to the wheel 41 by screwing the nut 32 onto the valve unit 30 with the wheel 41 sandwiched between the sensor unit 20 and the nut 32. It is caulked. Incidentally, the valve portion 30 and the nut 32 are formed of a conductive material such as stainless steel, for example. On the other hand, as shown in an enlarged view in FIG. 4, a groove 30c extending in the axial direction is formed in the side portion of the valve portion 30 so as to remove a part of the screw portions 30a and 30b. As shown in FIG. 5A, a wiring 34 whose outer periphery is covered with an insulating material such as a resin member is embedded in the groove 30c. That is, the wiring 34 is electrically insulated from the valve unit 30 and the like. Further, as shown in FIG. 5B, one end of the wiring 34 is exposed from the threaded portion 30 a of the valve portion 30 to become a contact a, and the other end is connected to the sensor portion 20. It is connected to a resistance detection circuit (not shown in FIG. 4) as a detection unit provided inside.

  On the other hand, as shown in FIG. 4, the sensor portion 20 is formed with an air hole 21 connected to the internal space of the valve portion 30. That is, the air sucked from the opening end 30 d of the valve unit 30 is guided from the internal space of the valve unit 30 to the inside of the tire through the air hole 21.

Incidentally, a battery (not shown) is built in the sensor unit 20, and an operating power source for the sensor unit U1 is secured by the battery.
Next, the resistance detection circuit will be described in detail with reference to FIGS. 6 and 7 show an equivalent circuit of the resistance detection circuit. FIG. 6 shows a state where the cap 31 is not attached to the valve unit 30, while FIG. 7 shows a state where the cap 31 is attached to the valve unit 30.

  As shown in FIG. 6, the resistance detection circuit includes a reference resistor Rre connected to the wiring 34 and a DC power source 22 connected in series to the reference resistor Rre. Among these, the DC power supply 22 obtains a power supply voltage from a battery built in the sensor unit U1, and outputs a constant DC voltage based on the potential of the valve unit 30. The resistance detection circuit detects a voltage applied to the reference resistor Rre through the voltage sensor 23a and detects a current flowing through the reference resistor Rre based on a voltage value detected through the voltage sensor 23a. 23 is also provided.

  In the resistance detection circuit having such a configuration, if the cap 31 is attached to the valve unit 30, the circuit operates as follows. First, as shown in FIG. 7, since the screw portion 30 a of the valve portion 30 contacts the screw portion 31 g formed on the inner surface of the cap 31, the contact point “a” of the wiring 34 contacts the inner surface of the cap 31. As a result, the resistance detection circuit is a circuit in which the reference resistance Rre and the electric resistance Rc of the cap 31 are connected in series with each other, as indicated by a two-dot chain line in the figure. A current i corresponding to Rc flows through the reference resistor Rre. In the resistance detection circuit, the value of the current i flowing through the reference resistor Rre is detected through the current sensor 23. As shown in FIG. 8, three types of caps shown in the following (a1) to (a3) are prepared for the cap 31 according to the magnitude of the electric resistance Rc.

  (A1) A normal cap 31a in which the electric resistance Rc is set in a range of “0 [Ω] ≦ Rc <10 [Ω]”. In addition, this normal cap 31a is formed, for example with alloys or compounds, such as aluminum and copper.

  (A2) A registration cap 31b in which the electric resistance Rc is set in a range of “10 [Ω] ≦ Rc <100 [kΩ]”. The registration cap 31b is formed of an alloy or a compound such as iron or tin.

  (A3) A stopping cap 31c in which the electric resistance Rc is set in a range of “100 [kΩ] ≦ Rc”. The stopping cap 31c is formed of, for example, a resin material or plastic.

Next, the system configuration of the sensor unit 20 will be described with reference to FIG. FIG. 9 shows a system configuration of the sensor unit 20 as a block diagram.
As shown in FIG. 9, the sensor unit 20 is provided with a transmission antenna 27 for wirelessly transmitting the detection signal. In addition to the current sensor 23, the sensor unit 20 is provided with an air pressure sensor 24 for detecting tire air pressure. The output signals of these sensors 23 and 24 are taken into a sensor-side control device 26 that is also provided in the sensor unit 20. The sensor-side control device 26 includes a non-volatile memory 26a as a storage unit in which the identification code ID1 is stored, and is a part that performs overall control of the sensor unit 20. Specifically, the sensor-side control device 26 first calculates the electrical resistance Rc of the cap 31 based on the current value detected through the current sensor 23. Note that the relationship between the current value detected through the current sensor 23 and the electrical resistance Rc of the cap 31 is obtained in advance by experiments or the like, and here, these relationships are mapped and stored in the memory 26a in advance. And the sensor side control apparatus 26 calculates | requires the electrical resistance Rc of the cap 31 based on the electric current value detected through the current sensor 23 by the map calculation by the map memorize | stored in the memory 26a. Further, as shown in FIG. 10, the operation mode of the sensor unit U1 is set to one of the following operation modes (b1) to (b3) according to the obtained value of the electric resistance Rc.

  (B1) When it is determined that the electric resistance Rc is in the range of “0 [Ω] ≦ Rc <10 [Ω]”. At this time, the sensor unit U1 is set to the normal mode. When the sensor unit U1 is set to the normal mode, the sensor-side control device 26 performs transmission control for generating the detection signal and intermittently transmitting the detection signal from the transmission antenna 27. As shown in FIG. 11A, the period for intermittently transmitting the detection signal is set to the first period T1.

  (B2) When it is determined that the electric resistance Rc is in the range of “10 [Ω] ≦ Rc <100 [kΩ]”. At this time, the sensor unit U1 is set to the registration mode. The sensor-side control device 26 generates a registration signal including a registration mode code indicating that the sensor unit U1 is set to the registration mode and the identification code ID1 when the sensor unit U1 is set to the registration mode. Is transmitted intermittently from the transmission antenna 27. As shown in FIG. 11B, the period for intermittently transmitting the registration signal is set to a second period T2 that is shorter than the first period T1.

  (B3) When it is determined that the electric resistance Rc is in the range of “100 [kΩ] ≦ Rc”. At this time, the sensor unit U1 is set to the stop mode. The sensor-side control device 26 stops the transmission of the detection signal and the registration signal when the sensor unit U1 is set to the stop mode.

  According to such sensor units U1 to U4, the operation mode of the sensor units U1 to U4 can be achieved by simply mounting any one of the normal cap 31a, the registration cap 31b, and the stop cap 31c on the valve unit 30. Can be changed. Thereby, since the operation mode of the sensor units U1 to U4 can be changed without using the dedicated tool described above, the operation mode of the sensor units U1 to U4 can be easily changed as compared with the prior art. . Therefore, the convenience of the dealer is improved.

  In addition, for example, the sensor units U1 to U4 can be set to the stop mode by attaching a stop cap 31c to the valve unit 30 at the time of manufacture or by removing the cap 31 from the valve unit 30. If the stop mode is set in this way, the sensor units U1 to U4 do not repeat transmission of the detection signal, so that the above-described battery consumption can be accurately suppressed. Further, when the sensor units U1 to U4 are used, if a normal cap 31a is attached to the valve unit 30, transmission of a detection signal is started from that point. Therefore, the functions required as the sensor units U1 to U4 can be satisfied.

  By the way, the attachment position of the tire of each wheel W1-W4 may be changed by the tire rotation performed at the time of vehicle inspection etc., for example. In such a case, the information illustrated in FIG. 2, that is, the registration information stored in the memory 12a of the vehicle-side control device 12, is updated according to the mounting positions of the sensor units U1 to U4 in the wheels W1 to W4. There is a need to. Therefore, in the present embodiment, when the user performs a specific operation on the vehicle, for example, by rotating the key inserted into the key cylinder of the vehicle in a specific manner, the in-vehicle device 10 receives the registration signal. It shifts to the state which permits reception. And if the vehicle-mounted apparatus 10 receives a registration signal in the state which has permitted reception of the registration signal, the content of the said registration information will be updated.

  FIG. 12 is a flowchart showing the procedure of the registration information update process executed by the vehicle-side control device 12. Next, a specific procedure of the process will be described with reference to FIG. Will be explained. This process is executed when a specific operation on the vehicle described above is detected. The value “N” is set to “1” as the initial value when this process is started.

  As shown in FIG. 12, in this process, first, after the information related to the identification code is deleted from the registration information exemplified in FIG. 2 (step S1), a registration signal is sent via the receiver 11. It is determined whether or not it has been received (step S2). In the process of step S2, specifically, it is determined that the registration signal has been received when the wireless signal received via the receiver 11 includes the registration mode code. When it is determined that the registration signal has been received (step S2: YES), it is determined whether or not the identification code included in the registration signal has already been registered in the registration information (step S2). S3) If already registered (step S3: YES), it is monitored again whether or not a registration signal has been received (step S2).

  On the other hand, when it is determined that the identification code included in the registration signal is not registered in the registration information (step S3: NO), the identification code included in the registration signal is the “N” th wheel. Is registered in the registration information as an identification code corresponding to the position (step S4). Incidentally, as shown in FIG. 13, the memory 12a of the vehicle-side control device 12 stores in advance the relationship between the value of “N” and the positions of the wheels W1 to W4. Based on the information shown in FIG. 13, the “N” th wheel is determined. That is, for example, when the value of “N” is “2”, the identification code included in the registration signal is registered in the registration information as the identification code of the left front wheel W2. In the subsequent step S5, the turn signal lamp 14 is flashed several times, the value of “N” is incremented (step S6), and the value of “N” reaches “5”. Is determined (step S7). If it is determined that the value of “N” has not reached “5” (step S7: NO), it is monitored again whether or not a registration signal has been received (step S2). On the other hand, when it is determined that the value of “N” has reached “5” (step S7: YES), the vehicle-side control device 12 ends this series of processing.

  FIGS. 14 and 15 show how the registration information is updated based on such processing by the vehicle-side control device 12. Hereinafter, referring to FIGS. 14 and 15, a tire pressure monitoring system will be described. Will be described in further detail.

  For example, when the user now has tires mounted on the wheels W1 to W4 of the vehicle as illustrated in FIG. 1, the tire of the right front wheel W1 and the tire of the right rear wheel W3 are exchanged. It is assumed that the tire rotation for exchanging the tire of the left front wheel W2 and the tire of the left rear wheel W4 is performed. In this case, as shown in FIG. 14, the sensor unit U1 moves to the right rear wheel W3, the sensor unit U2 moves to the left rear wheel W4, the sensor unit U3 moves to the right front wheel W1, and the sensor unit U4 moves to the left front wheel W2. To do.

  Then, after such tire rotation is performed, suppose that the user performs a specific operation on the vehicle, such as turning a key inserted into the key cylinder of the vehicle in a specific manner. The vehicle side control device 12 executes the registration information update process shown in FIG. Thereafter, if the user removes the normal cap 31a attached to the valve portion 30 of the right front wheel W1 and attaches the registration cap 31b to the valve portion 30, the registration signal including the identification code ID3 is sent to the sensor unit U3. Will be sent from. As a result, as shown in FIG. 15A, the identification code ID3 included in the registration signal is registered in the registration information as the identification code of the right front wheel W1. At this time, since the turn signal lamp 14 of the vehicle blinks several times, the user confirms that the registration of the identification code ID3 of the sensor unit U3 has been normally performed by watching the blinking of the turn signal lamp 14. can do. Note that after the identification code ID3 of the sensor unit U3 is once registered in the registration information, the identification code ID3 is not registered as the identification code of the other wheels W2 to W4. In addition, since the detection signal transmitted from the sensor units U1, U2, U4 does not include the registration mode code, the identification code included in the detection signal is not registered in the registration information. Therefore, only the identification code of a specific sensor unit can be reliably registered.

  Thereafter, when the user removes the normal cap 31a from the valve portion 30 of the left front wheel W2 and attaches the registration cap 31b to the valve portion 30, as shown in FIG. 15B, the sensor unit U4 is identified. The code ID4 is registered in the registration information as the identification code for the left front wheel W2. If the user then removes the normal cap 31a from the valve portion 30 of the right rear wheel W3 and attaches the registration cap 31b to the valve portion 30, as shown in FIG. 15 (c), the sensor unit U1 Is registered in the registration information as the identification code of the right rear wheel W3. Then, if the user removes the normal cap 31a from the valve portion 30 of the left rear wheel W4 and attaches the registration cap 31b to the valve portion 30, as shown in FIG. 15 (d), the sensor unit U2 Is registered in the registration information as the identification code of the left rear wheel W4. And the update of registration information is completed through such a series of registration operations by the user.

  According to such a sensor unit registration method, the registration caps 31b are arranged in a predetermined order, that is, “right front wheel W1 → left front wheel W2 → right rear wheel W3 → left rear wheel W4”. Registration information can be updated only by attaching to the valve unit 30. For this reason, such registration work can be easily performed.

  By the way, in such a tire pressure monitoring system, instead of the registration signal, for example, a method of registering the identification code of the sensor unit in the registration information using a detection signal can be considered. However, when the detection signal is used, the sensor unit identification code may be registered unless the period until the detection signal is transmitted from the sensor units U1 to U4, that is, the first period T1 at the longest. Because it may not be possible, registration may take a long time. In this regard, in the present embodiment, when the sensor units U1 to U4 are set to the registration mode, the registration signal including the identification code is transmitted in the second period T2 shorter than the first period T1, so that Thus, the time required for the registration work can be shortened, and as a result, work efficiency is improved.

  As described above, according to the sensor units U1 to U4 and the sensor unit registration method of the tire pressure monitoring system according to the present embodiment, the following effects can be obtained.

  (1) After providing a resistance detection circuit for detecting the electrical resistance of the cap 31, the operation mode of the sensor units U1 to U4 is changed based on the electrical resistance of the cap 31 detected through this resistance detection circuit. It was decided. Thereby, since the operation mode of the sensor units U1 to U4 can be changed without using the dedicated tool described above, the convenience of the dealer is improved.

  (2) In order to give the cap 31 electrical characteristics, the cap 31 is given electrical resistance. Thereby, it is possible to simplify the structure and reduce the cost of the cap 31 while providing the cap 31 with electrical characteristics.

  (3) The operation modes of the sensor units U1 to U4 include a normal mode for transmitting detection signals and a stop mode for stopping transmission of detection signals. Thereby, for example, the lifetime of the sensor unit can be improved by setting the operation mode of the sensor units U1 to U4 to the stop mode at the time of manufacture. Further, by setting the operation mode of the sensor unit to the normal mode during actual use, it is possible to satisfy the functions required for the sensor unit.

  (4) The operation mode of the sensor units U1 to U4 includes a registration mode for transmitting a registration signal including the identification codes ID1 to ID4. When the operation mode of the sensor units U1 to U4 is set to the normal mode, the detection signal is intermittently transmitted at the first cycle T1, and the operation mode of the sensor units U1 to U4 is set to the registration mode. The registration signal is intermittently transmitted in the second period T2 shorter than the first period T1. Thereby, if the operation mode of the sensor units U1 to U4 is set to the registration mode and the registration work is performed, the time required for updating the registration information can be shortened, so that the work efficiency is improved.

  (5) As a mounting member that is detachably mounted on the valve unit 30, a cap 31 that is screwed onto the valve unit 30 is used to suppress air leakage. As a result, it is not necessary to provide a new mounting member in the valve portion, so that the cost of the sensor unit can be reduced.

  (6) As a sensor unit registration method, the registration cap 31b is attached to the valve portions 30 of the wheels W1 to W4 in a predetermined order. When the registration signal is received by the in-vehicle device 10, the identification code included in the registration signal is associated with the position of each wheel in a predetermined order and registered as registration information. As a result, the registration information can be updated simply by attaching the registration cap 31b to the valve portions 30 of the wheels W1 to W4 in a predetermined order so that the registration work can be easily performed. Become.

<Second Embodiment>
Next, a second embodiment of the sensor unit according to the present invention will be described with reference to FIGS. The basic configuration of the sensor unit according to the second embodiment is similar to the configuration illustrated in FIGS. The basic configuration of the tire pressure monitoring system using the sensor unit according to the present embodiment is similar to the configuration illustrated in FIGS. 1 and 2 above.

  In the present embodiment, the electric circuit of the first embodiment is changed to a magnetic circuit. Specifically, a yoke is embedded in the cap 31, and a magnetic permeability detection circuit as a detection unit that detects the magnetic permeability without contact is provided in each of the sensor units U1 to U4. And the operation mode of sensor unit U1-U4 is changed based on the magnetic permeability detected through this magnetic permeability detection circuit.

  FIGS. 16 and 17 show equivalent circuits of the magnetic permeability detection circuit as diagrams corresponding to FIGS. 6 and 7 described above. 16 shows a state where the cap 31 is not attached to the valve unit 30, while FIG. 17 shows a state where the cap 31 is attached to the valve unit 30. In FIGS. 16 and 17, the same elements as those shown in FIGS. 6 and 7 are denoted by the same reference numerals, and redundant description is omitted. The following description focuses on the differences between the two. To do. Further, in FIG. 16 and FIG. 17, hatching indicating a cross section of the valve portion 30 is omitted for convenience.

  As shown in FIG. 16, a yoke 35 having a concave cross section is embedded in the bottom of the cap 31. Incidentally, the cap 31 is formed of a non-magnetic material such as rubber, for example. Further, as shown in FIG. 18, three types of caps shown in the following (c1) to (c3) are prepared for the cap 31 according to the magnetic permeability μc of the yoke 35. However, it is assumed that there is a relationship “μ1 <μ2” between the magnetic permeability μ1 and μ2.

(C1) A normal cap 31d in which the magnetic permeability μc of the yoke 35 is set in the range of “μc <μ1”.
(C2) A registration cap 31e in which the magnetic permeability μc of the yoke 35 is set in a range of “μ1 ≦ μc <μ2”.

(C3) A stopping cap 31f in which the magnetic permeability μc of the yoke 35 is set in the range of “μ2 ≦ μc”.
On the other hand, as shown in FIG. 16, the valve unit 30 is provided with an exciting coil 36 that forms an alternating magnetic field having a certain strength by energization from an AC power supply 28 provided in the sensor unit 20. The valve unit 30 is provided with a detection coil 37 connected to a reference resistor Rre provided in the sensor unit 20. Further, the valve unit 30 is provided with a magnetism collecting core 38 made of a magnetic material that collects and amplifies magnetism generated around the excitation coil 36 and the detection coil 37. The magnetic permeability detection circuit is configured by the circuit on the excitation coil 36 side and the circuit on the detection coil 37 side. Incidentally, the valve portion 30 is formed of a nonmagnetic insulating material such as a resin material.

  In the magnetic permeability detection circuit having such a configuration, when the cap 31 is attached to the valve unit 30, the circuit operates as follows. First, since a magnetic circuit is formed by the yoke 35 and the magnetic collecting core 38, as shown by a two-dot chain line in FIG. 17, the magnetic flux formed around the exciting coil 36 is changed to the yoke 35 and the magnetic collecting core 38. To the detection coil 37. Thereby, since an alternating magnetic field is applied to the detection coil 37, an induced electromotive force is generated in the detection coil 37. At this time, a current i corresponding to the magnitude of the induced electromotive force generated in the detection coil 37 flows through the reference resistor Rre, and the value of the current i is measured by the current sensor 23.

  By the way, in such a configuration, since the strength of the alternating magnetic field applied to the detection coil 37 changes according to the magnetic permeability μc of the yoke 35, it is detected through the magnetic permeability μc of the yoke 35 and the current sensor 23. There is a correlation between the current values. Therefore, in this embodiment, the magnetic permeability μc of the yoke 35 is obtained from the current value detected through the current sensor 23. Note that the relationship between the current value detected through the current sensor 23 and the magnetic permeability μc of the yoke 35 is obtained in advance by experiments or the like, and here, these relationships are mapped and incorporated in the sensor-side control device 26. Stored in advance in the memory 26a. Then, the control device 26 obtains the magnetic permeability μc of the yoke 35 based on the current value detected through the current sensor 23 by map calculation using a map stored in the memory 26a. Then, as shown in FIG. 19, the operation mode of the sensor unit U1 is set to one of the following operation modes (d1) to (d3) according to the obtained value of the magnetic permeability μc.

(D1) When it is determined that the magnetic permeability μc is in the range of “μc <μ1”. At this time, the sensor unit U1 is set to the normal mode.
(D2) When it is determined that the magnetic permeability μc is in the range of “μ1 ≦ μc <μ2”. At this time, the sensor unit U1 is set to the registration mode.

(D3) When it is determined that the magnetic permeability μc is in the range of “μ2 ≦ μc”. At this time, the sensor unit U1 is set to the stop mode.
The operation of the sensor unit U1 set in each mode is the same as that in the first embodiment. Such a configuration as a sensor unit is the same for the sensor units U2 to U4.

  Even with such sensor units U1 to U4, the operation mode of the sensor units U1 to U4 can be changed by simply mounting any one of the normal cap 31d, the registration cap 31e, and the stop cap 31f on the valve unit 30. Can be changed. Thereby, since the operation mode of the sensor units U1 to U4 can be changed without using the dedicated tool described above, the operation mode of the sensor units U1 to U4 can be easily changed as compared with the prior art. . Therefore, the convenience of the dealer is improved.

  In addition, for example, by attaching the stop cap 31f to the valve unit 30 at the time of manufacture, battery consumption can be accurately suppressed, so that the life of the sensor units U1 to U4 can be improved.

  As described above, according to the sensor units U1 to U4 and the sensor unit registration method of the tire pressure monitoring system according to the present embodiment, the effects (3) to (6) are the same as or equivalent to the effects. The following effects can be obtained.

  (7) After providing a magnetic permeability detection circuit for detecting the magnetic permeability of the cap 31, the operation modes of the sensor units U1 to U4 are determined based on the magnetic permeability of the cap 31 detected through the magnetic permeability detection circuit. I decided to change it. Thereby, since the operation mode of the sensor units U1 to U4 can be changed without using the dedicated tool described above, the convenience of the dealer is improved.

  (8) The yoke 31 is provided on the cap 31 so that the cap 31 has magnetic characteristics. Thereby, the magnetic permeability of the cap 31 can be changed simply by changing the magnetic permeability of the yoke 35, so that the magnetic characteristics of the cap 31 can be set easily and accurately.

  (9) An exciting coil 36 for applying an alternating magnetic field to the yoke 35 and a detection coil 37 for inducing an induced electromotive force according to the magnetic permeability of the yoke 35 when an alternating magnetic field is applied to the yoke 35 are provided. It was decided. The magnetic permeability of the cap 31 is detected based on the induced electromotive force induced in the detection coil 37. Thereby, the magnetic permeability of the cap 31 can be easily detected.

<Other embodiments>
In addition, each said embodiment can also be implemented with the following forms which changed this suitably.
In the first embodiment, the following configuration can be adopted. That is, the cap 31 is provided with a capacitor, and three types of caps are prepared according to the capacitance of the capacitor: the normal cap 31a, the registration cap 31b, and the stop cap 31c. The sensor unit 20 is provided with a detection circuit for detecting the capacitance of the capacitor provided in the cap 31 in place of the resistance detection circuit. And in the sensor side control apparatus 26, based on the electrostatic capacitance of the capacitor | condenser detected through a detection circuit, the operation mode of sensor unit U1-U4 is set in any of a normal mode, a registration mode, and a stop mode. In addition, after replacing with a capacitor | condenser and providing the coil in the cap 31, you may change the operation mode of sensor unit U1-U4 based on the reactance of a coil. Moreover, after giving the cap 31 an impedance, the operation mode of the sensor units U1 to U4 may be changed based on the impedance. In short, what is necessary is just to change the operation mode of the sensor units U <b> 1 to U <b> 4 based on the electrical characteristics of the cap 31. Even with such a configuration, it is possible to obtain an effect according to the first embodiment.

  In the first embodiment, the operation mode of the sensor units U1 to U4 is changed based on the electric resistance of the cap 31, but instead of this, for example, the electricity of the nut 32 illustrated in FIG. You may change the operation mode of sensor unit U1-U4 based on resistance. In addition, a mounting member other than the cap 31 and the nut 32 may be detachably provided on the valve unit 30, and the operation mode of the sensor units U1 to U4 may be changed based on the electrical resistance of the mounting member.

  In the second embodiment, the following configuration can be adopted. That is, a magnet is embedded in the cap 31, and three types of caps are prepared according to the strength of the magnet, the normal cap 31a, the registration cap 31b, and the stop cap 31c. The sensor unit 20 is provided with a detection circuit for detecting the strength of the magnet of the cap 31 in place of the resistance detection circuit. And in the sensor side control apparatus 26, based on the strength of the magnet detected through a detection circuit, the operation mode of sensor unit U1-U4 is set in any of a normal mode, a registration mode, and a stop mode. The point is that the operation mode of the sensor units U1 to U4 may be changed based on the magnetic characteristics of the cap 31. Even with such a configuration, it is possible to obtain an effect according to the second embodiment.

  In the second embodiment, the yoke 31 is provided on the cap 31, but instead, for example, the yoke 35 is provided on the nut 32 illustrated in FIG. The operation mode of the sensor units U1 to U4 may be changed based on the magnetic susceptibility. Further, a mounting member other than the cap 31 and the nut 32 may be provided in the valve unit 30 so as to be removable, and a yoke may be provided on the mounting member.

  In each of the above embodiments, when registering the identification codes ID1 to ID4 of the sensor units U1 to U4 in the registration information, the registration cap 31b is set to “right front wheel W1 → left front wheel W2 → right rear wheel W3 → left rear wheel. Although it was decided to be mounted on the valve unit 30 of each wheel in the order of “W4”, this order can be changed as appropriate.

  In each of the above embodiments, the turn signal lamp 14 is blinked when the identification code included in the registration signal is registered in the registration information. Alternatively, for example, the vehicle horn may be sounded. Good.

  In each of the above embodiments, the registration codes transmitted from the sensor units U1 to U4 are used to register the identification codes ID1 to ID4 of the sensor units U1 to U4 in the registration information. For example, a detection signal may be used. In this case, in the vehicle-side control device 12, it is effective to execute the registration information update process shown in FIG. 20 instead of the registration information update process exemplified in FIG. In the process shown in FIG. 20, it is determined whether or not the detection signal is received in the determination process in step S2 illustrated in FIG. 12, and is included in the detection signal in the determination process in step S3. It is determined whether or not the identification code is already registered in the registration information. In the process of step S4, the process of storing the identification code included in the detection signal in the memory 12a as the identification code corresponding to the position of the “N” th wheel is executed. On the other hand, the user may perform the following work when registering the identification code of the sensor unit. First, the user attaches a normal cap 31a only to the valve portion 30 of the right front wheel W1, and attaches a stopping cap 31c to the valve portions 30 of the other wheels W2 to W4, so that the right front wheel A detection signal is transmitted only from the sensor unit of W1. In this state, the user performs a specific operation on the vehicle, for example, by rotating the key inserted into the key cylinder of the vehicle in a specific manner. Thereby, in the vehicle side control apparatus 12, the registration information update process illustrated in FIG. 20 is executed, and the identification code included in the detection signal is registered in the registration information as the identification code corresponding to the right front wheel W1. After that, if the normal cap 31a is attached to the valve unit 30 of each wheel in the order of “left front wheel W2 → right rear wheel W3 → left rear wheel W4”, the identification code of the sensor unit of each wheel W1 to W4 is registered information. Registered in Even with such a configuration, the registration information can be updated simply by attaching the normal cap 31a to the valve portions 30 of the wheels W1 to W4 in a predetermined order. it can. In addition, when employ | adopting such a method, you may omit registration mode from the operation mode of sensor unit U1-U4.

  -Some tire pressure monitoring systems employ the following configuration. First, the vehicle is provided with an initiator that wirelessly transmits a command signal to each of the wheels W1 to W4. And sensor unit U1-U4 transmits the said detection signal based on reception of a command signal. In such a tire pressure monitoring system, the sensor units U1 to U4 may transmit a detection signal based on reception of a command signal when the normal mode is set.

  -The tire pressure monitoring system does not specify which of the wheels W1 to W4 has an abnormality, and warns when an abnormality of the air pressure is detected in any of the wheels W1 to W4. Some do. In such a tire pressure monitoring system, the registration information illustrated in FIG. 2 is not necessary, and the identification codes ID1 to ID4 of the sensor units U1 to U4 are registered when the tire rotation is performed. Work becomes unnecessary. The sensor unit according to the present invention can also be used in such a tire pressure monitoring system. In this case, the registration mode may be omitted from the operation mode of the sensor units U1 to U4.

<Appendix>
Next, a technical idea that can be grasped from each of the above embodiments and modifications thereof will be additionally described.
(A) In the sensor unit according to claim 5, the detection unit includes an excitation coil for applying an alternating magnetic field to the mounting member, and an attachment coil of the mounting member when the alternating magnetic field is applied to the mounting member. And a detection coil in which an induced electromotive force is induced according to the magnetic permeability, and the magnetic permeability of the mounting member is detected based on the induced electromotive force induced in the detection coil. Sensor unit. According to this configuration, it is possible to easily detect the magnetic permeability of the mounting member.

  (B) In the sensor unit according to any one of claims 1 to 7 and appendix i, a cap that is screwed to the valve portion as the mounting member so as to suppress air leakage from the air inlet. A sensor unit characterized by being diverted. According to this configuration, since it is not necessary to newly provide a mounting member in the valve portion, the cost of the sensor unit can be reduced.

  (C) The sensor unit according to any one of claims 1 to 7 and appendix (a), wherein the mounting member is a nut that is screwed onto the valve portion so as to caulk the sensor unit against a vehicle wheel. A sensor unit characterized by being diverted. According to this configuration, since it is not necessary to newly provide a mounting member in the valve portion, the cost of the sensor unit can be reduced.

  a ... contact, U1-U4 ... sensor unit, W1 ... right front wheel (wheel), W2 ... left front wheel (wheel), W3 ... right rear wheel (wheel), W4 ... left rear wheel (wheel), 10 ... in-vehicle device, DESCRIPTION OF SYMBOLS 11 ... Receiver, 12 ... Vehicle side control apparatus, 12a ... Memory, 13 ... Indicator, 14 ... Turn signal lamp, 20 ... Sensor part, 21 ... Air hole, 22 ... DC power supply, 23 ... Current sensor, 23a ... Voltmeter , 24 ... Air pressure sensor, 26 ... Sensor side control device, 26a ... Memory, 27 ... Transmission antenna, 28 ... AC power supply, 30 ... Valve part, 30a, 30b ... Screw part, 30c ... Groove, 30d ... Open end, 31 ... Caps 31a, 31d ... normal caps, 31b, 31e ... caps for registration, 31c, 31f ... caps for stopping, 31g ... screw parts, 32 ... nuts, 34 ... wiring, 35 ... yokes, 36 ... excitation Coil, 37 ... detection coil, 38 ... collector magnetizing core 40 ... tire, 41 ... wheel, 42 ... rim bottom.

Claims (9)

A valve portion serving as a tire air inlet, a sensor portion for detecting the tire air pressure, and a transmission antenna for wirelessly transmitting a detection signal including information on the tire air pressure detected through the sensor portion are integrated. In the sensor unit,
A mounting member that is detachably mounted on the valve unit, and a detection unit that detects an electrical characteristic or a magnetic characteristic of the mounting member, and the electrical characteristic or magnetism of the mounting member detected through the detection unit An operation mode for transmitting the detection signal from the transmission antenna is changed based on a target characteristic. The sensor unit according to claim 1, wherein the mounting member has a predetermined impedance as the electrical characteristic, and the detection unit detects an impedance of the mounting member. The sensor unit according to claim 2, wherein the mounting member has a predetermined electrical resistance as the impedance, and the detection unit detects an electrical resistance of the mounting member. The sensor unit according to claim 1, wherein the mounting member has a predetermined magnetic permeability as the magnetic characteristic, and the detection unit detects a magnetic permeability of the mounting member. The sensor unit according to claim 4, wherein the mounting member is provided with a yoke having a predetermined magnetic permeability, and the magnetic permeability of the mounting member is set based on the magnetic permeability of the yoke. The operation mode for transmitting the detection signal from the transmission antenna includes a normal mode for transmitting the detection signal and a stop mode for stopping transmission of the detection signal. The sensor unit according to item. The detection signal includes an identification code unique to the sensor unit,
The operation mode further includes a registration mode for wirelessly transmitting a registration signal including the identification code from the transmission antenna,
When the operation mode is set to the normal mode, the detection signal is intermittently transmitted at a first period, and when the operation mode is set to the registration mode, the registration signal is transmitted to the first mode. The sensor unit according to claim 6, wherein the sensor unit transmits intermittently at a second period shorter than one period. In separately monitoring the air pressure of the tire provided on each wheel of the vehicle by exchanging the detection signal between the sensor unit according to any one of claims 1 to 6 and the in-vehicle device provided in the vehicle. The sensor unit is provided separately for each wheel, and when transmitting the detection signal, the sensor unit includes a unique identification code in the detection signal, and the vehicle-mounted device includes the identification code. And storage means storing registration information indicating the relationship between the positions of the wheels, and when receiving the detection signal, based on the identification code included in the detection signal and the registration information In addition, it is determined which of the wheels the tire pressure information included in the detection signal is, and based on the determination result, the tire pressure of each wheel is individually monitored. The tire air pressure monitoring system which provides a said sensor unit registration method the identification code of the sensor unit in association with the position of said each wheel is registered in the storage means as the registration information,
The sensor unit transmits the detection signal when it is determined that the electrical property or magnetic property of the mounting member detected through the detection unit is a specific electrical property or magnetic property. ,
The in-vehicle device transmits the detection signal transmitted from the sensor unit of each wheel when the mounting member exhibiting the specific electrical characteristic or magnetic characteristic is mounted on the valve portion of each wheel in a predetermined order. When the tire pressure is received, the identification code included in the detection signal is associated with the position of each wheel in the predetermined order and is registered in the storage means as the registration information. System sensor unit registration method. In separately monitoring the air pressure of a tire provided on each wheel of the vehicle by exchanging the detection signal between the sensor unit according to claim 7 and an in-vehicle device provided in the vehicle, the sensor unit includes the Each wheel is provided separately, and when transmitting the detection signal, a unique identification code is included in the detection signal and transmitted, and the in-vehicle device includes the identification code, the position of each wheel, And when the detection signal is received, it is included in the detection signal based on the identification code and the registration information included in the detection signal. The tire pressure is used to determine which of the wheels the tire pressure information is on, and to monitor the tire pressure of each wheel based on the determination result. There viewing system, a sensor unit registration method for registering in the storage means the identification code as the registration information in association with the position of each wheel of the sensor unit,
The sensor unit transmits the registration signal when it is determined that the electrical property or magnetic property of the mounting member detected through the detection unit is a specific electrical property or magnetic property. ,
The vehicle-mounted device transmits the registration signal transmitted from the sensor unit of each wheel when the mounting member exhibiting the specific electrical characteristic or magnetic characteristic is mounted on the valve portion of each wheel in a predetermined order. When the tire pressure is received, the identification code included in the registration signal is associated with the position of each wheel in the predetermined order and is registered in the storage means as the registration information. System sensor unit registration method.

Images