JP2018024362A - Tire pressure monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide TPMS with which a user can accurately grasp not only when tire pressure has a failure but also whether tire pressure is a proper value or not and tire pressure is higher or lower through a display view.SOLUTION: A tire pressure monitoring system displays a level of high/low degree of tire pressure by a graphic display view in addition to indicating tire pressure in positions respectively corresponding to wheels 4a to 4d. Thus, a user can accurately grasp not only occurrence of a failure state but also whether displayed tire pressure is within a range of a proper value and higher or lower than the proper value based on the graphic display view.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a tire pressure monitoring system (hereinafter referred to as TPMS).

  The TPMS is an important system in terms of vehicle driving safety. In TPMS, a warning light indicated by a tire symbol mark is turned on or an alarm is sounded on a vehicle interior display to notify the user of an abnormality in tire air pressure. In TPMS, the tire pressure can be displayed numerically corresponding to each of the four wheels in the vehicle image by the display switching function of the display. If there is an abnormality in the tire pressure, the numerical value of the corresponding wheel is displayed in a different color to the numerical value of the other wheel so that the user can know the abnormality in the tire pressure. (See Patent Document 1).

JP2015-116913A

  However, warning lights and alarm warnings are issued after an abnormality has occurred in the tire pressure, and the current tire pressure, whether it is appropriate, higher or lower, is properly set. I can't know. Moreover, the general user does not remember the proper value of the tire pressure accurately, and confirms the proper value of the tire pressure through a sticker or the like attached to the vehicle. For this reason, when the tire pressure is simply displayed as a numerical value, the current tire pressure can be known, but whether the tire pressure is appropriate, high or low cannot be known only from the display.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a TPMS that can accurately grasp whether the tire pressure is abnormal or not higher than the appropriate value, not only when the tire pressure is abnormal through the display on the display. And

  In order to achieve the above object, the TPMS according to claim 1 is applied to a vehicle (1) in which a plurality of wheels (4a to 4d) having tires are attached to a vehicle body (5). A sensor transmitter (2) having a first control unit (22) that is provided for each of the plurality of wheels and detects a tire air pressure of each of the plurality of wheels and creates and transmits a frame storing data related to the tire air pressure; A receiving unit (31ba) that is provided on the vehicle body side and receives a frame transmitted from the sensor transmitter; a second control unit (31bb) that detects a tire air pressure of each of the plurality of wheels based on the received frame; 2 Degree display that displays the level of tire air pressure of each of the plurality of wheels detected by the control unit at a position corresponding to each of the plurality of wheels in a stepwise display display. Comprises a display device including (33b) and (33), a vehicle body-side system (3) having a, a.

  In this way, in addition to indicating the tire air pressure at the position corresponding to each wheel, the level of the tire air pressure level is displayed on the display. As a result, the user can not only grasp the abnormal case, but also accurately know whether the displayed tire pressure is within the appropriate value range or higher or lower than the appropriate value based on the display. It becomes possible to do.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a block block diagram when TPMS concerning 1st Embodiment of this invention is applied to a vehicle. It is a block block diagram of a sensor transmitter. It is a block block diagram of a vehicle body side system. It is the figure which showed the relationship between the encouragement pressure of a tire pressure, the range of an appropriate value, an upper limit threshold value, a lower limit threshold value, and the determination result of the tire pressure level by tire pressure monitoring. It is the figure which showed an example of the display display which displays the level of tire air pressure by a display apparatus. It is the flowchart which showed the detail of the tire pressure monitoring process. It is the figure which showed an example of the display display which displays the level of tire air pressure with the display apparatus demonstrated by other embodiment. It is the figure which showed an example of the display display which displays the level of tire air pressure with the display apparatus demonstrated by other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the TPMS according to the present embodiment. In FIG. 1, the upward direction in the drawing of FIG.

  As shown in FIG. 1, the TPMS is attached to the vehicle 1 and includes a sensor transmitter 2 and a vehicle body side system 3.

  As shown in FIG. 1, one sensor transmitter 2 is attached to each wheel 4 a to 4 d in the vehicle 1. Specifically, the sensor transmitter 2 detects the air pressure of the tire attached to the wheels 4a to 4d and the temperature in the tire, and stores the data of the detection signal indicating the detection result in the transmission frame and transmits it. To do. The vehicle body side system 3 is provided on the vehicle body 5 side of the vehicle 1 and receives a frame transmitted from the sensor transmitter 2 and performs various processes and computations based on data stored therein. I am looking for tire pressure. The vehicle body side system 3 alerts the user that the tire air pressure is abnormal, thereby alerting the user. Furthermore, in the vehicle body side system 3, for example, tire pressure display is performed based on a user operation, and whether the tire air pressure of each of the wheels 4a to 4d is an appropriate value or higher or lower than the appropriate value. You can check it.

  Detailed configurations of the sensor transmitter 2 and the vehicle body side system 3 will be described with reference to FIGS. 2 and 3.

  As shown in FIG. 2, the sensor transmitter 2 includes a sensing unit 21, a microcomputer 22, a battery 23, and a transmission antenna 24.

  The sensing unit 21 includes, for example, a diaphragm type pressure sensor and a temperature sensor, and outputs a detection signal (hereinafter referred to as a detection signal related to tire air pressure) indicating the tire air pressure and the temperature in the tire. The sensing unit 21 detects the tire air pressure and the temperature in the tire for each predetermined detection cycle based on a command from the microcomputer 22.

  The microcomputer 22 is a well-known computer having a CPU, ROM, RAM, I / O, and the like, and executes predetermined processing according to a program stored in the ROM. Specifically, the microcomputer 22 includes a control unit 22a, a transmission unit 22b, and the like, and performs various processes related to tire pressure monitoring according to a program stored in a built-in memory of the control unit 22a.

  The control unit 22a receives a detection signal related to the tire air pressure from the sensing unit 21 every predetermined detection period, processes the signal, and processes it as necessary. And the control part 22a is stored in the frame together with the unique identification information (hereinafter referred to as ID information) of each sensor transmitter 2 as data indicating the detection result (hereinafter referred to as data relating to tire air pressure). The data is sent to the transmitter 22b. The process of sending a signal to the transmitter 22b is executed at predetermined intervals according to the program.

  The transmission unit 22 b functions as an output unit that transmits a frame transmitted from the control unit 22 a to the receiver 31 through the transmission antenna 24.

  The battery 23 supplies power to the control unit 22a and the like, and receives power supply from the battery 23, collects data related to tire pressure in the sensing unit 21, and performs various calculations in the control unit 22a. Is executed.

  The sensor transmitter 2 configured as described above is attached to an air injection valve in each of the wheels 4a to 4d, for example, and is arranged so that the sensing unit 21 is exposed inside the tire. Thereby, the tire air pressure of the corresponding wheel is detected, and the frame is transmitted every predetermined transmission cycle, for example, every minute, through the transmission antenna 24 provided in each sensor transmitter 2.

  In addition, about the data regarding tire pressure, it is sent with ID information of each sensor transmitter 2 with which the vehicle was equipped. The position of each wheel can be specified by a known wheel position detection device that detects which position of the vehicle the wheel is attached to. For this reason, it is possible to determine which wheel data is by transmitting data related to tire air pressure together with ID information to the receiver 31.

  As shown in FIG. 3, the vehicle body side system 3 includes a receiver 31, an operation switch 32, and a display device 33. Each part which comprises the vehicle body side system 3 is connected through in-vehicle LAN (abbreviation of Local Area Network) by CAN (abbreviation of Controller Area Network) communication etc., for example. For this reason, each part can communicate with each other through the in-vehicle LAN.

  The receiver 31 includes a receiving antenna 31a and a microcomputer 31b.

  The receiving antenna 31 a is one or more antennas that collectively receive frames transmitted from the sensor transmitters 2, and is fixed to the vehicle body 5.

  The microcomputer 31b is a well-known one having a CPU, a ROM, a RAM, an I / O, and the like, and executes a predetermined process according to a program stored in the ROM. Specifically, the microcomputer 31b includes a receiving unit 31ba and a control unit 31bb, and performs various processes related to tire pressure monitoring according to a program stored in a built-in memory of the control unit 31bb.

  The receiving unit 31ba functions as an input unit that receives a frame from each sensor transmitter 2 received by the receiving antenna 31a and sends the frame to the control unit 31bb.

  The control unit 31bb obtains the tire pressure by performing various signal processing and computations based on the data related to the tire pressure stored in the received frame, and determines a decrease in the tire pressure based on the tire pressure.

  Specifically, the control unit 31bb determines whether the tire air pressure of each of the wheels 4a to 4d is an appropriate value or larger or smaller than the appropriate value. The appropriate value of the air pressure is determined based on the recommended pressure, for example, and is stored in a built-in memory (not shown) of the control unit 31bb.

  For example, it is stored in the built-in memory of the control unit 31bb when the microcomputer 31b is manufactured, or is registered in the built-in memory of the control unit 31bb in an automobile manufacturer's automobile manufacturing factory or an automobile sales dealer. It can be memorized.

  If the detected tire pressure is within the range of the appropriate value, the control unit 31bb determines that the tire pressure is the appropriate value and is “appropriate”. Further, the control unit 31bb determines that the pressure is “slightly higher” if the detected tire pressure is within the pressure range from the upper limit value of the appropriate value to the upper limit threshold value set as a value higher than the upper limit value. If it exceeds the upper threshold, the pressure is determined to be “higher”. Further, the control unit 31bb determines that the pressure is “slightly lower” if the detected tire pressure is within the pressure range from the lower limit value of the appropriate value range to the lower limit threshold value set as the alarm threshold value lower than the lower limit value. If it is less than the lower limit threshold, the pressure is low, that is, “abnormal” is determined.

  For example, as shown in FIG. 4, a recommended pressure −10 kPa to a recommended pressure +20 kPa is set as an appropriate value range based on the recommended pressure, and a value higher than the upper limit value of the appropriate value range, for example, recommended pressure +40 kPa is set as an upper limit threshold value. . Further, a value lower than the lower limit value of the appropriate value range, for example, recommended pressure × 0.8 kPa is set as the lower limit threshold value. For this reason, if the acquired tire pressure changes like the value plotted in the figure, the tire pressure will be `` higher '', `` slightly higher '', `` appropriate '', `` slightly lower '', `` abnormal '' according to the tire pressure Is determined as follows. Since the detected tire pressure may include an error due to a manufacturing error of the sensing unit 21 or the like, the lower limit threshold includes recommended pressure × 0.8 + margin including a margin based on the error. It is preferable.

  In this way, the control unit 31bb determines whether the tire air pressure of each of the wheels 4a to 4d is within the appropriate value range, higher or lower than the appropriate value range, or abnormal. Etc. are judged. Then, the data indicating the determination result is transmitted to the display device 33.

  Such tire pressure monitoring is performed, for example, when a tire pressure display display request (hereinafter referred to as a user request) is made by a user operation through the operation switch 32. However, it is also possible to display the tire air pressure of the wheels 4a to 4d when a user request is made while displaying the abnormality of the tire air pressure regardless of the presence or absence of the user request. In this case, the control unit 31bb determines whether the tire air pressure is within the appropriate value range, higher or lower than the appropriate value range, or abnormal, regardless of whether there is a user request. . If the control unit 31bb determines that the abnormality is present, even if there is no user request, the control unit 31bb outputs a signal to that effect to the display device 33, so that the tire pressure is indicated to the user as “abnormal”. Tell. In addition, when the control unit 31bb makes a determination other than “abnormal”, the tire pressures of the wheels 4a to 4d and whether the tire pressures are within the appropriate range only when a user request is made. Data relating to whether the value is higher or lower than the appropriate value range is transmitted to the display device 33. By doing so, it is possible to display the tire air pressure of the wheels 4a to 4d when there is a user request while displaying the abnormality of the tire air pressure regardless of whether there is a user request. .

  As described above, the recommended pressure and the range of appropriate values are stored in the built-in memory of the control unit 31bb. However, even if these parameters are not stored, other parameters may be stored, and the recommended pressure, appropriate value range, etc. may be calculated from the parameters and registered in the built-in memory. For example, a lower limit threshold value that is an alarm threshold value is stored in a built-in memory, and a recommended pressure can be calculated from the lower limit threshold value. As described above, when the recommended pressure × 0.8 + margin is the lower limit threshold, the recommended pressure is calculated by (lower limit threshold−margin) /0.8. Then, with this recommended pressure as a reference, for example, -10 kPa to +20 kPa can be set as the appropriate value range.

  Furthermore, after a user or a dealer or the like adjusts the tire pressure, a specific operation can be performed through an operation switch 32 or a display device 33 described later, and an appropriate value range can be registered by the operation based on the user operation. .

  The operation switch 32 corresponds to an operation unit, and performs a request for display of tire pressure and a display switching operation based on a user operation. Here, although the operation switch 32 is shown as a separate body from the display device 33, the display device 33 may be provided with the function of the operation switch 32, that is, the function as an operation unit. For example, the operation switch 32 may be provided in a part of the display device 33, or the display provided in the display device 33 may be a touch panel type, as will be described later, so that a tire pressure display display request can be made by touch panel operation. Anyway.

  The display device 33 is disposed at a place where a driver who is a user can visually recognize the vehicle while driving, and is installed, for example, in an instrument panel in the vehicle 1. The display device 33 is composed of, for example, a meter display and the like, and performs display related to tire pressure to the driver. Specifically, the display device 33 determines whether the tire pressure of the wheels 4a to 4d from the control unit 31bb is within the appropriate value range, higher or lower than the appropriate value range, Receive data on whether or not something is wrong. And the display apparatus 33 performs the display display regarding a tire pressure based on the received data. When the operation by the operation switch 32 is a user-requested condition, the display device 33 displays this display when it is confirmed that the operation switch 32 has been operated and a user request has been made.

  Specifically, as shown in FIG. 5, in addition to the display of the vehicle 1, an air pressure display unit 33 a that displays the numerical value of the tire air pressure at a location corresponding to each of the four wheels 4 a to 4 d is provided. And the degree display part 33b which displays the level of the level of tire air pressure by a graphic display under each air pressure display part 33a is provided. In the case of the present embodiment, the degree display unit 33b performs display using a circular dot graphic in which each dot is circular as five dot graphic corresponding to each of the wheels 4a to 4d. More specifically, the degree display unit 33b uses five circular dot figures to change the lighting position and display color according to the level of tire pressure of each wheel 4a to 4d, thereby changing the degree of elevation to five levels. Is displayed.

  For example, among the five circular dot figures, the leftmost is a state in which the tire air pressure is lower than the lower threshold, and the second from the left is the state in which the tire air pressure is equal to or higher than the lower threshold but lower than the appropriate value range, The middle shows the state where the tire pressure is within the range of the appropriate value. Of the five circular dot figures, the second from the right indicates that the tire pressure does not exceed the upper threshold, but is higher than the appropriate range, and the rightmost indicates that the tire pressure exceeds the upper threshold. ing. That is, the five left figures are “abnormal” on the left, “slightly low” on the second from the left, “reasonable” on the middle, “slightly high” on the second from the right, and “high” on the right. It shows the level of high and low.

  The display color of each circular dot figure may be the same, but for example, “abnormal” or “high” is red, “slightly low” or “slightly high” is yellow, and “proper value” is blue. It is.

  As described above, the display device 33 according to the present embodiment displays the tire pressure as a numerical value at a location corresponding to each of the four wheels 4a to 4d, and lights up one of the circular dot figures, thereby increasing the tire pressure. Graphic display.

  The display device 33 may be configured to have a buzzer, a voice guidance function, and the like. In that case, the display device 33 audibly gives the driver a tire pressure that is “abnormal” or a tire pressure that is “appropriate”, “higher”, “slightly higher”, “slightly lower”. ”Can be notified. In addition, although the meter display device is exemplified as the display device 33 that performs visual notification, the display device 33 may be configured by a display device that displays information such as a head-up display.

  As described above, the TPMS in the present embodiment is configured. Subsequently, an operation example of the TPMS configured as described above will be described. However, since the tire pressure detection by the sensor transmitter 2 and the transmission of data related to the tire pressure from the sensor transmitter 2 to the vehicle body side system 3 in the operation of the TPMS are the same as the conventional ones, the tire pressure is here. The display display method will be mainly described.

  First, the control unit 22a of the sensor transmitter 2 performs tire pressure monitoring processing for each predetermined control cycle, and transmits a frame storing data related to tire pressure at a predetermined periodic transmission timing. The vehicle body side system 3 receives a frame transmitted by the sensor transmitter 2 when an ignition switch (not shown) is turned on. Thereby, the tire air pressure of each wheel 4a-4d is detected in the control part 31bb of the receiver 31. FIG. Then, in the control unit 31bb, the tire pressure of each wheel 4a to 4d is “abnormal” or the tire pressure is determined by comparing with the lower limit threshold value or the upper limit threshold value or determining whether it is within the range of the appropriate value. Whether “appropriate”, “higher”, “slightly higher”, or “slightly lower” is determined. Specifically, the controller 31bb performs this determination by executing the tire pressure monitoring process shown in FIG. 6 for each predetermined control cycle.

  First, as shown in step S100, tire pressure is acquired by reading out data related to tire pressure from the frame transmitted from the sensor transmitter 2. When the temperature in the tire is included as data related to the tire pressure, it can be converted into the tire pressure at a predetermined temperature based on Boyle Charles' law. Since the ID information is stored in the frame transmitted from the sensor transmitter 2, the sensor transmitter 2 that has transmitted the frame is attached to any of the wheels 4a to 4d based on the ID information. It can be specified whether it is a thing.

  And it progresses to step S105 and it is determined whether it is in the range of the appropriate value acquired by step S100. If an affirmative determination is made here, the process proceeds to step S110 to determine “appropriate”. If a negative determination is made, the process proceeds to step S115.

  In step S115, it is determined whether or not the tire air pressure acquired in step S100 is greater than the appropriate value range. If an affirmative determination is made here, the process proceeds to step S120, and it is further determined whether or not the tire air pressure exceeds the upper limit threshold value. If an affirmative determination is made, the process proceeds to step S125 to determine "high" and a negative determination is made. If so, the process proceeds to step S130 to determine “slightly higher”. Further, if a negative determination is made in step S115, the process proceeds to step S135, further determines whether or not the tire air pressure is less than the lower limit threshold value, and if an affirmative determination is made, the process proceeds to step S140 to determine “abnormal”. If a negative determination is made, the process proceeds to step S145 to determine “slightly lower”.

  When it is determined whether the tire pressure is “abnormal”, “appropriate”, “higher”, “slightly higher”, or “slightly lower” in this way, the process proceeds to step S150, and the determination result is displayed. This is transmitted to the display device 33 together with the tire pressure.

  In this way, the tire pressure monitoring process is completed. Such tire pressure monitoring processing is executed every time data related to tire pressure is sent from the sensor transmitter 2, that is, for each of the wheels 4a to 4d. Then, when the determination result and the tire pressure are transmitted from the receiver 31 to the display device 33, the display device 33 displays the result. That is, the tire air pressure is displayed in a form corresponding to each of the wheels 4a to 4d, and the tire air pressure is displayed as either “abnormal”, “appropriate”, “higher”, “slightly higher”, or “slightly lower” by the graphic display. Is displayed in a form that can be grasped.

  For example, when the recommended pressure is 200 kPa and the appropriate value range and the upper and lower thresholds are set as shown in FIG. 4, the right front wheel 4a, the left front wheel 4b, the right rear wheel 4c, the left rear wheel It is assumed that the tire pressure of 4d is 200, 180, 150, and 230 kPa in order. In this case, it is determined that the right front wheel 4a is “appropriate”, the left front wheel 4b is “slightly low”, the right rear wheel 4c is “abnormal”, and the left rear wheel 4d is “slightly high”. Therefore, as shown in FIG. 5, the tire air pressure is indicated at a location corresponding to each of the wheels 4a to 4d, and a display corresponding to the tire air pressure is performed using a graphic display under each tire air pressure. That is, for the right front wheel 4a, the middle of the five circular dot graphics is lit in blue, and for the left front wheel 4b, the second from the left of the five circular dot graphics is lit in yellow. Further, for the right rear wheel 4c, the leftmost of the five circular dot shapes is lit red, and for the left rear wheel 4d, the second from the right of the five circular dot shapes is lit yellow.

  Further, in order to more clearly notify the user of “abnormal”, as shown in FIG. 5, for example, the tire pressure is surrounded by yellow, so that a warning is displayed for a wheel whose tire pressure is less than the warning threshold. Can also be done.

  As described above, in the TPMS according to the present embodiment, in addition to showing the tire air pressure at positions corresponding to the wheels 4a to 4d, the level of the tire air pressure level is displayed by a graphic display. . As a result, the user can not only grasp the abnormal case, but also accurately grasp whether the displayed tire pressure is within the appropriate value range or higher or lower than the appropriate value based on the graphic display. It becomes possible to do.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  (1) For example, in the said embodiment, a figure display is mentioned as an example as one of the forms which display the level of tire air pressure in steps, Furthermore, the circular dot figure which is an example of a dot-like figure as a figure display is mentioned. Explained. The present invention is not limited to this, and other stepwise display displays can be applied, and other graphic displays can be applied. Furthermore, other dot-like figures, such as a square dot figure in which square dots are arranged, a star dot figure in which star dots are arranged, and the like can also be applied.

  Other graphic displays include analog displays. For example, as shown in FIG. 7A, the uniaxial scale is divided into five areas of “abnormal”, “slightly low”, “appropriate”, “slightly high”, and “high”, and the line-shaped display corresponds to the tire pressure. It is also possible to display the degree of tire air pressure by expanding and contracting.

  Moreover, as shown in FIG. 7B, the tire pressure of the tire can be divided by dividing it into five areas of “abnormal”, “slightly lower”, “appropriate”, “slightly higher”, and “higher” such as a sector or circular meter. A form in which the height is displayed may be used. In this case, the level of the tire air pressure can be displayed by rotating the pointer display with respect to the center of the circle according to the tire air pressure. Further, if the tire air pressure value is displayed on the outer periphery of the arc, the tire air pressure value can be accurately recognized. Here, “abnormal”, “slightly lower”, “appropriate”, “slightly higher”, and “higher” are not displayed in each partitioned area, but these displays may also be performed together. Furthermore, as shown in FIG. 7B, by providing a number corresponding to each of the wheels 4a to 4d of FL to RR, it becomes possible to accurately recognize the level of tire pressure of each of the wheels 4a to 4d.

  7A is not displayed corresponding to each of the wheels 4a to 4d. However, in the case where the display form of FIG. It is possible to accurately recognize the level of each tire pressure.

  Moreover, it is also possible to display graphics such as animals and flowers. For example, in the case of “abnormal”, the condition that animals and flowers are likely to fall down, and in the case of “slightly low”, the degree of fall is less than in the case of “abnormal”. Corresponding graphic display can also be performed.

  Furthermore, it is also possible to display characters according to the tire pressure together with graphic display. For example, the characters “abnormal”, “slightly lower”, “appropriate”, “slightly higher”, and “higher” can be put under the graphic display.

  (2) Further, in the above embodiment, when the data related to the tire pressure transmitted from the sensor transmitter 2 includes temperature data other than the tire pressure, the tire pressure at the predetermined temperature is converted into the appropriate value. It was compared with the upper limit threshold value and the lower limit threshold value whether it was in the range. On the other hand, the recommended tire air pressure, the range of appropriate values, and the upper and lower thresholds may be corrected based on the sent temperature data.

  (3) The appropriate value may be variable according to the type of road on which the vehicle is traveling. Specifically, the recommended pressure is higher when the vehicle is traveling on a highway than when the vehicle is traveling on a general road. For this reason, for example, when a vehicle travels on an expressway, the recommended pressure set when traveling on a general road is set to, for example, + 10%, and an appropriate range, upper threshold and lower threshold are set. Each value can be set to a value corresponding to the type of road on which the vehicle is traveling.

  It should be noted that the adjustment of each value according to the type of road to be traveled is performed when a user operation is performed through the operation switch 32 or the like, or road information and the current position of the vehicle are acquired from the navigation system. And can be made based on that.

DESCRIPTION OF SYMBOLS 2 Sensor transmitter 3 Car body side system 4a-4d Wheel 21 Sensing part 22 Microcomputer 31 Receiver 31b Microcomputer 32 Operation switch 33 Display apparatus

Claims (6)

Applied to a vehicle (1) in which a plurality of wheels (4a to 4d) having tires are attached to a vehicle body (5);
A sensor transmitter (1) provided on each of the plurality of wheels, and having a first control unit (22) for detecting and transmitting a tire pressure of each of the plurality of wheels and generating a frame storing data related to the tire pressure. 2) and
A receiving unit (31ba) that is provided on the vehicle body side and receives a frame transmitted from the sensor transmitter, and a second control unit (31bb) that detects a tire air pressure of each of the plurality of wheels based on the received frame. And a degree display unit (33b) for displaying the level of tire air pressure of each of the plurality of wheels detected by the second control unit at a position corresponding to each of the plurality of wheels in a stepwise display display. A tire pressure monitoring system comprising: a display device (33) including the vehicle body side system (3).   The tire pressure monitoring system according to claim 1, wherein the display device performs the stepwise display display by graphic display.   The display device graphically displays the level of tire air pressure of each of the plurality of wheels by a plurality of dot-shaped figures, and changes the lighting position of the plurality of dot-shaped figures according to the height. The tire pressure monitoring system according to claim 2.   The tire pressure monitoring system according to claim 2 or 3, wherein the display device changes a display color of the plurality of dot-shaped figures in accordance with the height.   The display device includes an air pressure display unit (33a) for displaying a numerical value of a tire air pressure of each of the plurality of wheels, and graphically displays a level of the tire air pressure of each of the plurality of wheels together with the numerical value of the tire air pressure. Item 5. The tire pressure monitoring system according to any one of Items 2 to 4.   6. The display device according to claim 1, wherein, in addition to the graphic display, a warning display indicating that the tire air pressure is reduced is performed for a wheel of which the tire air pressure is less than an alarm threshold among the plurality of wheels. The tire pressure monitoring system according to any one of the above.

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