JP2005212620A - Tire air pressure monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire air pressure monitoring device of a vehicle for notifying tire air pressure by notification sound to facilitate an air filling work. <P>SOLUTION: A monitoring device body 9 is constituted of an air pressure determining part 92 for performing an air pressure determination based on a detection result inputted from an input interface 91, an output command signal generating part 93 for generating an output command signal based on the determination result of the air pressure determining part 92, and an output interface 94 connected with a speaker 53, etc. When tire air pressure starts to rise, the output command signal generating part 93 recognizing a change of tire air pressure outputs a notification sound output signal to the speaker 53 via the output interface 94 after generating a notification sound output signal for only the tire. As a result, the notification sound starts to be produced from the speaker 53 when a worker starts the air filling work, for instance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tire pressure monitoring device that facilitates air filling work and the like.

  In addition to the structure and state of the suspension device and the steering device, the steering stability of the automobile greatly depends on the tire air pressure (tire pressure) that is a contact point with the road surface. For example, in a tire whose tire air pressure has decreased, a decrease in rigidity, an increase in contact area, and an increase in contact length are unavoidable, so that the ability to follow steering is significantly reduced. In addition, a decrease in tire air pressure causes tire temperature rise and standing wave during high-speed driving, and also causes deterioration in driving fuel consumption, so it is strictly prevented from driving comfort and economy. There is a need. Usually, automobile drivers and operation managers often check and manage tire pressures using an air charger (air gauge) such as a gas station.

For example, the air filling operation for a tire having a decreased tire pressure is performed in the following procedure. The worker stops the vehicle at a predetermined position such as a pit and then measures the tire air pressure of each wheel using an air gauge. If there is a wheel whose tire air pressure has decreased, an air charger filling nozzle (see, for example, Patent Document 1) is pressed against the tire valve, and an air gauge pointer attached to the air charger body (or digital display) The air is filled so that the tire air pressure becomes a specified value. Various automatic air filling devices that set a target air pressure and automatically stop air supply when the tire air pressure reaches the target air pressure have been proposed (see, for example, Patent Document 2).
Japanese Patent Laying-Open No. 2003-95076 (paragraph 0007, FIG. 1) Japanese Patent Laying-Open No. 2003-335114 (paragraphs 0017 to 0025, FIG. 3)

  As described above, the air filling operator performs air filling by pressing the filling nozzle held with one hand against the tire valve while looking at the pointer of the air gauge and the digital display. For this reason, tireless work may result in overfilling of the tire air pressure exceeding an appropriate value. In this case, it is necessary to start air filling again after exhausting air to some extent. In particular, when air is filled in a dark place at night or the like, it is difficult to read the air gauge pointer and digital display, so that work efficiency is reduced and overfilling is likely to occur. On the other hand, in the automatic air filling device described in Patent Document 2, such overfilling can be prevented, but the device cost becomes high and the target air pressure needs to be set for each vehicle.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle tire pressure monitoring device that notifies the tire pressure with a notification sound, thereby facilitating air filling work and the like. To do.

A tire pressure monitoring device according to a first aspect of the present invention is provided in a vehicle body, and is provided in the vehicle body, receiving means for receiving a radio signal transmitted from an air pressure sensor unit mounted on a wheel of the vehicle, and the vehicle body. Based on the reception result of the receiving means, air pressure determining means for determining the air pressure of the tire mounted on the wheel, and determining whether the tire is filled with air is provided on the vehicle body An air filling determination means and a notification provided on the vehicle body, and outputting a notification sound based on the determination result of the air pressure determination means when the air filling determination means determines that the tire is being filled with air And a sound output means.
In the tire air pressure monitoring device according to claim 1, for example, when the tire air pressure reaches an appropriate value during the air filling operation, the air pressure determining means determines this based on the detection result of the air pressure sensor unit inputted from the receiving means, and the notification sound The output means outputs a notification sound that air filling should be stopped based on the determination result.

Further, in the tire air pressure monitoring device according to claim 2, in the tire air pressure monitoring device according to claim 1, the notification sound output means outputs the notification sound at least when the air pressure is a predetermined value. It is characterized by that.
In the tire pressure monitoring device according to the second aspect, the notification sound is output from the notification sound output means at the time when the tire pressure becomes an appropriate value, for example, during the air filling operation.

Further, the tire pressure monitoring device according to the invention of claim 3 is the tire pressure monitoring device according to claim 2, wherein the notification sound output means, as the air pressure approaches the predetermined value from the low pressure side, It is characterized in that at least one of the output pitch, pitch, tone color and volume of the notification sound is changed.
In the tire air pressure monitoring device according to claim 3, for example, when an operator performs an air filling operation on a tire whose tire air pressure has decreased, as the tire air pressure approaches an appropriate value, the pitch of the notification sound is shortened and the pitch is also increased. Become.

According to a fourth aspect of the present invention, there is provided the tire pressure monitoring apparatus according to the second or third aspect, wherein the notification sound output means increases the air pressure beyond the predetermined value. Then, at least one of the output pitch, pitch, tone color and volume of the notification sound is changed.
In the tire pressure monitoring device according to claim 4, for example, when the operator performs an air filling operation on a tire having a decreased tire pressure, as the tire pressure increases beyond an appropriate value, the pitch of the notification sound becomes shorter. The volume increases.

A tire pressure monitoring apparatus according to a fifth aspect of the present invention is the tire pressure monitoring apparatus according to any one of the first to fourth aspects, wherein the notification sound output means is provided in a side mirror device of the vehicle. It is characterized by that.
In the tire pressure monitoring apparatus according to the fifth aspect, for example, when an operator performs an air filling operation on a tire having a decreased tire pressure, a notification sound corresponding to the tire pressure is emitted from a speaker provided in the door mirror.

A tire pressure monitoring apparatus for a vehicle according to a sixth aspect of the invention is the tire pressure monitoring apparatus according to any one of the first to fifth aspects, wherein the air pressure is displayed on a side mirror device of the vehicle. The display means for performing is provided.
In the tire pressure monitoring device according to claim 6, for example, when an operator performs an air filling operation on a tire having a decreased tire pressure, the operator recognizes a change in the tire pressure by a notification sound, and more accurately by a digital display of the display means. Check tire pressure.

  According to the tire pressure monitoring apparatus of the first aspect, for example, an operator who performs an air filling operation can recognize the tire pressure from the notification sound without looking at the display of the air gauge. Further, according to the tire pressure monitoring device of claim 2, for example, an operator who performs an air filling operation recognizes that the tire pressure has reached a specified value by an alarm sound without looking at the display of the air gauge. it can. Further, according to the tire pressure monitoring apparatus of the third aspect, for example, an operator who performs the air filling operation can recognize the completion of the air filling operation or the like by a change in the notification sound. Moreover, according to the tire pressure monitoring apparatus of the fourth aspect, for example, an operator who performs an air filling operation can recognize that the overfilling has occurred due to a change in the notification sound. Moreover, according to the tire pressure monitoring apparatus of the fifth aspect, the notification sound is likely to reach the worker who performs the air filling operation on the side of the vehicle. According to the tire pressure monitoring apparatus of claim 6, for example, an operator who performs an air filling operation can set the tire pressure to an arbitrary value other than a specified value by looking at the digital display on the display means. it can.

  Hereinafter, an embodiment of a tire pressure monitoring apparatus for a vehicle according to the present invention will be described. The vehicle tire pressure monitoring device of the embodiment receives a radio signal (detection result) from an air pressure sensor unit attached to each wheel of a four-wheeled vehicle by an antenna built in a door mirror device, and tires are received from the received detection result. A configuration in which the air pressure monitoring device body generates an air pressure display signal and a notification sound output signal, and the tire pressure is digitally displayed on a display integrated with the door mirror body, while a notification sound is output from a speaker built in the door mirror device. Have taken.

<Embodiment>
1 is a plan view showing a device configuration of a vehicle according to the embodiment, FIG. 2 is a circuit configuration diagram of a pneumatic sensor, FIG. 3 is a perspective view showing a door mirror device, and FIG. 4 is a tire according to the embodiment. FIG. 5 is a block diagram showing the configuration of the air pressure monitoring device main body, and FIG. 5 is a conceptual diagram for explaining the operation of the embodiment.

<Vehicle device configuration>
First, a device configuration of a vehicle according to the present embodiment will be described with reference to FIG. In the description, for the four wheels and members arranged corresponding thereto, that is, tires, air pressure sensor units, etc., subscripts indicating front, rear, left, and right are attached to the reference numerals, for example, wheel 2fl ( Left front), wheel 2fr (right front), wheel 2rl (left rear), wheel 2rr (right rear), and generically referred to as wheel 2, for example. On the other hand, for members installed on the left and right sides of the vehicle, that is, speakers, vehicle body side antennas, etc., subscripts indicating the left and right are attached to the numerical symbols, and the speaker 53L (left) and speaker 53R (right) are written. When referring generically, for example, the speaker 53 is described.

  As shown in FIG. 1, a vehicle (passenger car in this embodiment) 1 includes four wheels 2 on which tires 21 are mounted, and a tire pressure monitoring system that measures tire pressure and tire temperature on each wheel 2. The air pressure sensor unit 3 is mounted. The vehicle 1 also includes a door mirror device (side mirror device) 4 with a door mirror side antenna 51, a display (display means) 52, and a speaker (notification sound output means) 53 of a tire air pressure monitoring system. In addition to (Electronic Control Unit) 7, a warning device 8 (warning lamp 81 and warning buzzer 82) of the tire pressure monitoring system and a maintenance switch 54 are mounted.

  The in-vehicle ECU 7 includes a microcomputer, a ROM, a RAM, a peripheral circuit, an input / output interface, various drivers, and the like, and a tire pressure monitoring device via a communication line (CAN (Controller Area Network) in this embodiment). Are connected to the door mirror side antenna 51, the display 52, the speaker 53, the maintenance switch 54, and the warning device 8. The warning device 8 causes the driver to recognize the decrease in tire air pressure by turning on the warning lamp 81 and sounding the alarm buzzer 82 when the tire air pressure of any of the wheels 2 decreases during traveling. In the case of the present embodiment, the warning lamp 81 has a total of four lamps on the front, rear, left and right sides, and can indicate the position of the wheel 2 where the tire air pressure has decreased.

  The air pressure sensor unit 3 is a tire valve integrated type, and as shown in FIG. 2, a CPU (Central Processing Unit) 31, a pressure sensor 32 that generates an output signal corresponding to the tire air pressure, and a temperature in the tire And a temperature sensor 33 for generating an output signal. Output signals from the pressure sensor 32 and the temperature sensor 33 are converted into digital values via an A / D (Analog / Digital) conversion circuit (not shown) and input to the CPU 31.

  The air pressure sensor unit 3 includes a power source (lithium battery or the like) 34, and this power source 34 functions as an operating source for the CPU 31 and the like. The air pressure sensor unit 3 includes a sensor-side antenna 35 having a transmission / reception function, and receives an activation signal transmitted from the door mirror-side antenna 51 (see FIG. 1) via the sensor-side antenna 35, while pressure The detection results (pressure information and temperature information) of the sensor 32 and the temperature sensor 33 are transmitted to the door mirror side antenna 51.

  For example, a 315 MHz PCM (Pulse Code Modulation) digital radio wave signal is transmitted from the sensor-side antenna 35 of the air pressure sensor unit 3. Although not shown, the power supply circuit between the power supply 34 and the CPU 31 is provided with a voltage sensor and outputs a signal corresponding to the output voltage of the power supply 34. The output of the voltage sensor is also A / D converted and input to the CPU 31.

  As shown in FIG. 3, the door mirror device 4 is made of a resin mirror stay 41 fixed to the base of the front pillar, and a resin mirror supported on the mirror stay 41 through a rotating shaft 42 so as to be swingable in the front-rear direction. The mirror body 43 and a mirror main body 44 held in the mirror body 43 are provided. The mirror body 43 is driven between a rear-view position (a position where the mirror main body 44 faces rearward) and a storage position (a position where the mirror main body 44 faces the vehicle body) by an electric storage mechanism (not shown), while a clutch (not shown). Due to this action, it can be tilted by manual operation between the retracted position and the reverse position (position where the mirror main body 44 faces sideward). In FIG. 3, reference numeral 45 is a fine hole that functions as a speaker grille, and is formed in the mirror body 43.

  In the case of the present embodiment, the door mirror side antenna 51 has a rod shape, and is housed in the lower part of the mirror body 43. The effective length of the door mirror side antenna 51 is a value corresponding to the wavelength of the radio wave transmitted from the sensor side antenna 35 (see FIG. 2) in order to improve the reception sensitivity (for example, 1/8 or 1 of the wavelength of the radio wave). / 4, 1/2). The door mirror side antenna 51 is not limited to the rod shape, and may have a loop shape, a U shape, an S shape, a W shape, or the like, or may be covered with a conductive coating material on the lower surface of the mirror stay 41. You may make it stick, and you may make it attach a loading coil in order to ensure effective length.

  The display 52 is a color liquid crystal panel integrated with the mirror main body 44, and the tire pressure of each wheel is indicated by the blinking of the tire in the figure (plan view of the car) and the digital (green) of the tire pressure (KPa). When the tire air pressure falls below a predetermined value (for example, 140 KPa), the digital display is displayed in red.

<Configuration of tire pressure monitoring device body>
Next, with reference to FIG. 4, the structure of the tire pressure monitoring device main body (hereinafter abbreviated as the monitoring device main body) built in the in-vehicle ECU 7 (see FIG. 1) will be described.
The monitoring device main body 9 includes an input interface 91, and a door mirror side antenna 51 and a maintenance switch 54 are connected to the input interface 91. The monitoring device body 9 also includes an air pressure determination unit (air pressure determination unit) 92 that performs air pressure determination based on the detection result input from the input interface 91, and an output that generates an output command signal based on the determination result of the air pressure determination unit 92. A command signal generation unit (air filling determination means, notification sound output means) 93, and an output interface 94 to which the warning device 8, the display 52, and a speaker (notification sound output means) 53 are connected.

<Operation of Embodiment>
Hereinafter, the operation of this embodiment will be described with reference to FIGS.
[Inspection of tire pressure]
An operator 100 such as a maintenance shop shown in FIG. 5 first turns on the maintenance switch 54 (see FIGS. 1 and 3) in the passenger compartment when the tire 21 is filled with air. Then, as shown in FIG. 4, the maintenance signal Smt from the maintenance switch 54 is input to the output command signal generation unit 93 of the monitoring apparatus main body 9 via the input interface 91, and the output command signal generation unit 93 outputs the air pressure sensor unit. An activation signal Sw is generated. The activation signal Sw is input to the door mirror side antenna 51 via the output interface 94 and transmitted from the door mirror side antenna 51 to the air pressure sensor unit 3 of each wheel 2.

  In each air pressure sensor unit 3 to which the start signal Sw is input, the pressure sensor 32 (see FIG. 2) detects the tire air pressure P, while the temperature sensor 33 (see FIG. 2) detects the tire internal temperature T. The detection result is transmitted together with the ID of the air pressure sensor unit 3 from the sensor side antenna 35 (see FIG. 2).

  Then, as shown in FIG. 4, the detection result (Pfl, Tfl) of the air pressure sensor unit 3fl and the detection result (Prl, Trl) of the air pressure sensor unit 3rl are received by the left side door mirror side antenna 51L, and the air pressure sensor unit 3fr The detection result (Pfr, Tfr) and the detection result (Prr, Trr) of the air pressure sensor unit 3rr are received by the right door mirror side antenna 51R.

  The detection result of each air pressure sensor unit 3 is received by the door mirror side antenna 51 and then input to the air pressure determination unit 92 via the input interface 91. In the air pressure determination unit 92, a temperature correction operation and a comparison operation with the air pressure decrease determination threshold value are performed, and these operation results are output to the output command signal generation unit 93.

  When the maintenance switch 54 is operated, the output command signal generator 93 generates an air pressure display signal corresponding to each wheel 2 and outputs the air pressure display signal to the display 52 via the output interface 94.

  As a result, as shown in FIG. 5, the tire pressure of each wheel 2 is sequentially displayed on the display 52 together with the position (flashing of the tire in the figure) at a predetermined interval (for example, every 3 seconds). 100 can easily confirm this by looking at the display 52. As described above, when the tire air pressure becomes a predetermined value (for example, 140 KPa) or less on the display 52, the digital is displayed in red. Therefore, the operator 100 recognizes the decrease in the tire air pressure. If necessary, perform air filling work.

[Air filling work]
As shown in FIG. 5, the worker 100 presses the nozzle of the air charger 101 against the tire valve (the air pressure sensor unit 3) when the wheel 2 having a decreased tire air pressure exists. Then, compressed air from an air source (not shown) flows into the tire 21 (the tire 21rr on the right rear wheel side in FIG. 5) via the air charger 101, and the tire air pressure of the wheel 2 starts to increase.

  In the case of this embodiment, when the tire air pressure of any tire 21 starts to rise, the output command signal generation unit 93 (see FIG. 4) that recognizes the change in the tire air pressure displays the air pressure display signal only for the tire 21. And the notification sound output signal, the air pressure display signal is output to the display 52 via the output interface 94 (see FIG. 4), while the notification sound output signal is output to the speaker 53. Here, the notification sound output signal has a value corresponding to the deviation between the current tire air pressure and the target air pressure, and is calculated by the output command signal generator 93 using a predetermined arithmetic expression. Thus, for example, when the worker 100 starts the air filling operation of the right rear wheel side tire 21rr, the tire air pressure of the right rear wheel side tire 21rr is digitally displayed on the left and right displays 52L and 52R, while the speaker 53 A notification sound begins to be emitted.

  As a result, the worker 100 recognizes the progress of the air filling work from the notification sound from the speaker 53, and efficiently checks the tire air pressure by digital display on the display 52, thereby efficiently performing the air filling work on the tire 21. It can be carried out. In FIG. 5, since the worker 100 fills the right rear wheel side tire 21rr with air, the mirror body 43 (see FIG. 3) is in the rear view position. When the tire 21fr is filled with air, the worker 100 may set the mirror body 43 to the reverse position so that the display 52 can be seen.

  From the speaker 53 of the present embodiment, when the set air pressure (for example, 210 KPa) of the wheel 2 on which the air filling operation is performed is set as the target air pressure, the following is performed according to the deviation between the current tire air pressure and the target air pressure. A notification sound is emitted. In other words, when the tire pressure approaches the target pressure from the low pressure side, the notification sound gradually decreases in output pitch (for example, “Puu, Puu” → “Pue, Pew” → “Puu, Puu” → “Pue, Puu” ) And its pitch gradually increases. The notification sound is emitted at a moment when the tire air pressure reaches the target air pressure, with a relatively large volume and a different tone (for example, like a beep). Thereby, the worker 100 can recognize the completion of the air filling work without paying attention to the digital display on the display 52. Further, when the tire air pressure starts to increase beyond the target air pressure, the speaker 53 gives a notification sound (for example, the output pitch gradually decreases and the sound volume increases with a different tone from that when approaching the target air pressure from the low pressure side (for example, , “Bee, Bie” → “Bee, Bie” → “Bi, Bi” → “Bi, Bi, Bi”), and the worker 100 recognizes overfilling.

≪Modification≫
Hereinafter, some modified examples of the present embodiment will be described. All of the modified examples relate to the notification sound emitted from the speaker 53, and there is no change in the device configuration and the like of the vehicle 1.
<First Modification>
The following notification sound is emitted from the speaker 53 of the first modification. That is, the notification sound of the first modified example is a continuous tone of a constant tone, and is emitted so that the volume gradually decreases as the tire air pressure approaches the target air pressure from the low pressure side, and the tire air pressure reaches the target air pressure. It is emitted for a short time at a relatively large volume at a moment, and when the tire pressure rises above the target air pressure, it is emitted so that the volume gradually increases as opposed to the forefront. That is, in the first modification, the volume of the notification sound increases as the difference between the tire air pressure and the target air pressure increases, so that the worker 100 reduces the notification sound to the target air pressure. You can get closer. The tone and pitch when the tire air pressure approaches the target air pressure from the low pressure side may be different from the tone and pitch when the tire air pressure exceeds the target air pressure.

<Second Modification>
The following notification sound is emitted from the speaker 53 of the second modification. That is, the notification sound of the second modification is a synthesized voice, and when the tire air pressure approaches the target air pressure from the low pressure side, a numerical value of the tire air pressure (for example, “193”, (Such as “197” and “201”) is issued by the soprano, and at the moment when the tire air pressure reaches the target air pressure, a stop audio notification (for example, “filling stop”) is issued and the tire air pressure exceeds the target air pressure. As a result, tire pressure values (for example, “215”, “221”, and “227”) are emitted from the baritone at a predetermined utterance interval (for example, 1.5 seconds).

  The description of the specific embodiments is finished above, but the aspects of the present invention are not limited to these embodiments and modifications. For example, in the embodiment, the output command signal generation unit 93 uses the arithmetic expression to notify the notification sound. Although the output signal is calculated, it may be obtained from a notification sound output signal map or the like stored in storage means such as a ROM. In the embodiment and the first modification, the output pitch and volume of the notification sound are changed when the tire air pressure approaches the target air pressure from the low pressure side and when the tire air pressure exceeds the target air pressure. However, the notification sound may be output only at the moment when the target air pressure is reached. Further, the notification sound output means may be other than the speaker such as a buzzer, or may be installed other than the door mirror device such as a fender mirror device or a wheel house. In addition, the specific configuration and the like of the vehicle and the monitoring device main body can be appropriately changed as long as they do not depart from the spirit of the present invention.

It is a top view which shows the apparatus structure of the vehicle which concerns on embodiment. It is a circuit block diagram of an air pressure sensor. It is a perspective view which shows a door mirror apparatus. It is a block diagram which shows the structure of a tire pressure monitoring apparatus main body. It is a conceptual diagram for demonstrating the effect | action of embodiment.

Explanation of symbols

1 Vehicle 2 Wheel 3 Air Pressure Sensor Unit 4 Door Mirror Device (Side Mirror Device)
8 Warning equipment 9 Monitoring device body (Air pressure judgment means, air filling judgment means)
21 tire 51 door mirror side antenna (reception means)
52 Display (display means)
53 Speaker (notification sound output means)

Claims (6)

Receiving means for receiving a radio wave signal transmitted from an air pressure sensor unit provided on a vehicle body and mounted on a wheel of the vehicle;
An air pressure determining means provided on the vehicle body, for determining an air pressure of a tire mounted on the wheel based on a reception result of the receiving means;
An air filling determining means provided on the vehicle body for determining whether or not an air filling operation is performed on the tire;
A notification sound output means provided on the vehicle body for outputting a notification sound based on a determination result of the air pressure determination means when the air filling determination means determines that the tire is being filled with air; Tire pressure monitoring device characterized by that.   The tire pressure monitoring device according to claim 1, wherein the notification sound output means outputs the notification sound at least when the air pressure is a predetermined value.   The notification sound output means changes at least one of an output pitch, a pitch, a tone color, and a volume of the notification sound as the air pressure approaches the predetermined value from a low pressure side. 2. The tire pressure monitoring apparatus according to 2.   3. The notification sound output means changes at least one of an output pitch, a pitch, a tone color, and a volume of the notification sound as the air pressure exceeds the predetermined value. Or the tire pressure monitoring apparatus according to claim 3.   The tire pressure monitoring device according to any one of claims 1 to 4, wherein the alarm sound output means is provided in a side mirror device of the vehicle.   The tire pressure monitoring device according to any one of claims 1 to 5, wherein a display means for displaying the air pressure is provided on a side mirror device of the vehicle.

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