Tire inflation pressure monitoring apparatus

• US 8,731,771 B2
• Filed: 04/18/2013
• Issued: 05/20/2014
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kusunoki, Hideki, Ohashi, Hideki
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): NELSON, SARA J
• Application Number:
  US13/865,527
• Publication Number:
  US 20130297144A1
• Time in Patent Office: 397 Days
• Field of Search: 701/29.1, 701/30.8, 701/34.4, 701/33.4, 340/438, 340/442, 340/444, 731/46, 731/462
• US Class Current: 701/34.4
• CPC Class Codes: B60C 23/00 Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
• CPC Class Codes: B60C 23/02 Signalling devices actuated by tyre pressure hand-held tyre pressure gauges G01L17/00
• CPC Class Codes: B60C 23/0401 characterised by the type of alarm
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0474 Measurement control, e.g. setting measurement rate or calibrating of sensors; Further processing of measured values, e.g. filtering, compensating or slope monitoring
• CPC Class Codes: G01M 17/02 Tyres

Abstract

A tire inflation pressure obtaining unit obtains tire inflation pressure. An inflation pressure storing unit stores a tire inflation pressure after start of travel of a vehicle as an after-travel inflation pressure. A pressure reduction determining unit determines reduction in the tire inflation pressure based on the tire inflation pressure obtained. A reference pressure setting unit sets larger one of the after-travel inflation pressure and a predetermined lowest reference pressure as a reference pressure of tire inflation pressure determination when reduction in the tire inflation pressure is determined, and sets the lowest reference pressure as a reference pressure of tire inflation pressure determination when reduction in the tire inflation pressure is not determined. An alarm unit generates an alarm when the tire inflation pressure becomes below an alarm pressure threshold which is determined from the reference pressure.

Claims

1. A tire inflation pressure monitoring apparatus comprising:

a tire inflation pressure obtaining unit which obtains tire inflation pressure;

an inflation pressure storing unit which stores the tire inflation pressure after start of travel of a vehicle as an after-travel inflation pressure;

a pressure reduction determining unit which determines reduction in the tire inflation pressure based on the tire inflation pressure obtained;

a reference pressure setting unit which sets larger one of the after-travel inflation pressure and a predetermined lowest reference pressure as a reference pressure of tire inflation pressure determination when reduction in the tire inflation pressure is determined, and sets the lowest reference pressure as the reference pressure of tire inflation pressure determination when reduction in the tire inflation pressure is not determined; and

an alarm unit which generates an alarm when the tire inflation pressure becomes below an alarm pressure threshold which is determined from the reference pressure.

2. The tire inflation pressure monitoring apparatus according to claim 1, wherein

the inflation pressure storing unit stores, as an after-travel inflation pressure, the tire inflation pressure when the vehicle travels at a vehicle speed equal to or higher than a predetermined speed for predetermined accumulation time.

3. The tire inflation pressure monitoring apparatus according to claim 2, further comprising a vehicle speed determining unit which shortens an interval of obtaining the tire inflation pressure when the predetermined accumulation time is reached.