Abstract: An indirect tire pressure monitoring system is provided that estimates a pressure in a tire more accurately than before. The system includes an estimated internal pressure transmitter (control unit) that calculates and transmits an estimated internal pressure of a tire when a vehicle is travelling based on a wheel speed, a measured internal pressure of the tire at halt and a measured temperature of the tire at halt. The system measures the internal pressure and the temperature for each tire, and carries out deflation evaluation independently for each tire.

Abstract: An indirect tire pressure monitoring system is provided that estimates a pressure in a tire more accurately than before. The system includes an estimated internal pressure transmitter (control unit) that calculates and transmits an estimated internal pressure of a tire when a vehicle is travelling based on a wheel speed, a measured internal pressure of the tire at halt and a measured temperature of the tire at halt. The system measures the internal pressure and the temperature for each tire, and carries out deflation evaluation independently for each tire.

Abstract: A system for detecting deflated tires by making a relative comparison among rotation speeds of tires attached to a vehicle. The system includes a rotation speed information detection means for detecting rotation speed information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; and a determination means for determining deflated tires by comparing a decreased pressure determination value using the calculated rotation speeds with a predetermined threshold value. The determination means determines that the vehicle is going straight when it is found, with regard to factors composed of a lateral G, a yaw rate, and a steering angle of the vehicle, at least two of the factors including the yaw rate show that a difference between the maximum value and the minimum value at a predetermined time is lower than a predetermined value, thereby detecting deflated tires.

Abstract: A system detects deflated tires based on a resonance frequency of tires with a vehicle and a relative comparison value of rotation speeds of the tires. The system includes: a rotation information detection means for detecting rotation information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; a resonance frequency assumption means for assuming a resonance frequency of the tires; and a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency. The determination means is so configured as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is represented by A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8; and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is represented by B index=E*/tan ??120.

Abstract: A system detects deflated tires based on a resonance frequency of tires with a vehicle and a relative comparison value of rotation speeds of the tires. The system includes: a rotation information detection means for detecting rotation information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; a resonance frequency assumption means for assuming a resonance frequency of the tires; and a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency. The determination means is so configured as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

Abstract: A system for detecting deflated tires by making a relative comparison among rotation speeds of tires attached to a vehicle. The system includes a rotation speed information detection means for detecting rotation speed information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; and a determination means for determining deflated tires by comparing a decreased pressure determination value using the calculated rotation speeds with a predetermined threshold value. The determination means determines that the vehicle is going straight when it is found, with regard to factors composed of a lateral G, a yaw rate, and a steering angle of the vehicle, at least two of the factors including the yaw rate show that a difference between the maximum value and the minimum value at a predetermined time is lower than a predetermined value, thereby detecting deflated tires.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is found by: A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8??relational expression (1); and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is found by: B index=E*/tan ??120??relational expression (2).