Toyota Jidosha Kabushiki Kaisha

Yuji Taki

Hideki Murakami

Tomoyuki Ishikawa

Provided is a replacement necessity determination device for a snap-in valve having an inner end to which an air pressure detection device including an air pressure sensor and an acceleration sensor is coupled. A control device of the replacement necessity determination device is configured to predict an angle change amount of the snap-in valve and the air pressure detection device with respect to a wheel caused by a centrifugal force based on a rotational speed of the wheel and an acceleration detected by the acceleration sensor, calculate a degradation indication value of an elastic body of the snap-in valve based on a maximum value of the angle change amount during a period set in advance, and determine necessity of replacement of the snap-in valve based on an integrated value of the degradation indication value.

Replacement necessity determination device for snap-in valve

A tire pressure detector includes: an air pressure detector to repeatedly detect air pressure of a target tire; a transmission device to wirelessly transmit air pressure information about the air pressure detected by the air pressure detector; a reception device to receive the air pressure information transmitted by the transmission device; an estimation device to calculate, when the reception device receives the air pressure information on the identical target tire a plurality of times, an estimated air pressure based on a plurality of pieces of the latest air pressure information received by the reception device, the estimated air pressure being an estimated value of the air pressure at current time; and an alarm generation device to raise an alarm when the estimated air pressure becomes equal to or less than a specified threshold.

Tire pressure detector

It should be enabled to transmit tire-pressure information also on a spare wheel to a tire-pressure notification device, while suppressing battery consumption. A transmission controller of a sensor unit makes a transmitter periodically transmit wheel information, when an acceleration Gx detected by an acceleration sensor is larger than a running-judgment threshold value 5G. The transmission controller accumulates a point P set up according to the acceleration Gx in a predetermined period when the acceleration Gx is not more than the running-judgment threshold value 5G, and makes the transmitter transmit the wheel information when an accumulated value of the point P accumulated in the predetermined period is larger than a running-track-record-judgment threshold value.

Tire-pressure sensor unit, a tire-pressure notification device, and vehicle

A warning control unit of this tire air pressure monitoring device starts giving a driver a tire air pressure fall warning when a tire air pressure is equal to or lower than a first threshold. The warning control unit stops the warning when the tire air pressure becomes equal to or higher than a second threshold that is set based on a tire temperature in a case where the warning is being given. The warning control unit uses a constant value unrelated to a detected tire temperature as the first threshold, and uses a value obtained by adding a variable value, which is obtained by adding a positive constant value to a value that increases as a temperature difference obtained by subtracting a tire temperature at the time of the issuance of the warning from a current tire temperature increases, to the first threshold, as the second threshold.

Tire air pressure monitoring device

A pulse count part acquires the minimum value among the numbers of pulse signals outputted by respective wheel-speed sensors during a wheel speed is within a minute low speed range. The pulse count part sets said minimum value as the numbers of the pulse signals of respective wheel-speed sensors during the wheel speed is within the minute low speed range, when the wheel speed increases out of said minute low speed range. Thereby, even when a vehicle stops in the middle of a wheel location discrimination treatment, a wheel location discrimination treatment can be continued using a proper pulse count value.

Tire-pressure monitoring device

[Objective] Unreceived malfunction should be prevented from being reported, at the time of a set replacement of tires. [Means for Solution] About each registered sensor ID, the unreceived malfunction judging portionoutputs a malfunction signal to the notification controller, when an unreceived period exceeds first setup time Tref. The total unreceived period calculation portionoutputs a self-vehicle ID discrimination initiation instruction to ID discrimination/rewriting portion, when the sum total unreceived period Ttotal which is the sum total of the unreceived period of each registered sensor ID is calculated and the sum total unreceived period Ttotal exceeds second setup time Tref. Before an unreceived period exceeds first setup time Tref, registered sensor ID is rewritten and it can avoid reporting unreceived malfunction to a driver by this.

Tire-pressure monitor system

A tire-pressure information device should receive wheel information within a demanded detection time. A transmission controller of a sensor unit transmits wheel information as a radio signal at the timing when the turning position &#x3b8; of the sensor unit detected by an acceleration sensor arrives at the transmission setting location &#x3b1; after 1 minute has passed since the last transmission of the wheel information. This transmission setting location &#x3b1; is set to a turning position which is advanced or retarded a setting adjustment angle &#x394;&#x3b1; (for instance, 146 degree) set to a value which is not a divisor of 360, with respect to the turning position &#x3b8; when the last wheel information is transmitted last time.

Tire-pressure sensor unit and a tire-pressure information device

A vehicle wheel information acquiring device includes a vehicle wheel sensor and a vehicle-body-side device. The vehicle wheel sensor is configured to revolve around an axle with a rotation of a vehicle wheel. The vehicle-body-side device includes a reception unit, a processing unit, a rotation position acquiring unit, an on-reception rotation position storage unit, and a determination unit. The determination unit is configured to determine whether a revolution position of the vehicle wheel sensor is included in an insufficient received intensity area during a stopping operation of a vehicle.

Vehicle wheel information acquiring device

A tire trouble detection device detects occurrence of a trouble in a tire. The tire trouble detection device comprises a detection unit which detects a change of state of a layered composition portion arranged in layers inside an outer sheath forming an outside surface of the tire, the layered composition portion forming a frame of the tire. A determination unit receives a result of the detection from the detection unit and determines occurrence of a trouble of the layered composition portion based on the received result of the detection.

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Miyoshi, Japan

Yuji Taki