Tire inflation pressure detection device

• US 9,776,461 B2
• Filed: 06/16/2014
• Issued: 10/03/2017
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Okada, Noriaki, Watabe, Nobuya, Mori, Masashi
• Primary Examiner(s): Alam, Mirza
• Application Number:
  US14/908,389
• Publication Number:
  US 20160167459A1
• Time in Patent Office: 1,205 Days
• CPC Class Codes: B60C 23/0445 Means for changing operating mode, e.g. sleep mode, factory mode or energy saving mode
• CPC Class Codes: B60C 23/0455 Transmission control of wireless signals
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol
• CPC Class Codes: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Abstract

In a tire inflation pressure detection device, a receiver functions such that, when an ignition switch is on, power is generated by a power supply controller to set the power supply state of the receiver to one in which frame reception is enabled to detect the inflation pressure of a tire, and such that, when the IG is off, in each predetermined intermittent cycle power is generated by the power supply controller to set the power supply state of the receiver to one in which frame reception is enabled to detect the inflation pressure of the tire. A transmitter determines whether a decrease in tire inflation pressure occurs, and when the decrease occurs, the transmitter transmits frames more frequently than before the occurrence of the decrease in tire inflation pressure at a shorter frame transmission time interval than a regular transmission cycle during a high-frequency transmission period.

Claims

1. A tire inflation pressure detection device, comprising:

a plurality of transmitters correspondingly provided to a plurality of wheels which are respectively equipped with a tire, and each of the plurality of transmitters having;

a sensor that outputs a detection signal relating to a tire inflation pressure of each corresponding wheel,

a first controller that forms data relating to the tire inflation pressure by applying signal processing to the detection signal of the sensor and creates a frame in which the data is stored, and

a radio transmitter that transmits the frame in a predetermined regular transmission cycle; and

a receiver provided to a vehicle body side, and having;

a radio receptor that receives the frame,

a power-supply controller that controls a power supply to enable a reception of the frame at the radio receptor, and

a second controller that detects an occurrence of a decrease of the tire inflation pressure based on the data relating to the tire inflation pressure stored in the frame which is received, wherein;

the receiver operates on a supply of power from a battery and detects the tire inflation pressure while an ignition switch is in an on state by generating the power supply to enable the reception of the frame at the radio receptor using the power-supply controller to change a power-supply state of the receiver to a state in which the receiver is enabled to receive the frame, and detects the tire inflation pressure while the ignition switch is in an off state by generating the power supply to enable the reception of the frame at the radio receptor using the power-supply controller in every predetermined intermittent cycle to change the power-supply state of the receiver to the state in which the receiver is enabled to receive the frame;

each of the plurality of transmitters determines based on the detection signal of the sensor whether a decrease of the tire inflation pressure occurs, and transmits, when a decrease of the tire inflation pressure occurs, the frame at a frame transmission time interval less than the regular transmission cycle during a high-frequency transmission zone set to be greater than or equal to the predetermined intermittent cycle at a frequency higher than a frequency before a decrease of the tire inflation pressure occurs; and

the predetermined regular transmission cycle is set to be shorter than a reception enable cycle during which the receiver changes the power-supply state of the receiver to the state in which the receiver is enabled to receive the frame in the every intermittent cycle.

2. The tire inflation pressure detection device according to claim 1, wherein:

the reception enable cycle is set to be greater than or equal to a total of a frame transmission time interval of the transmitters during the high-frequency transmission zone and a frame time length of one frame.

3. The tire inflation pressure detection device according to claim 2, wherein:

the reception enable cycle is set to be greater than or equal to the predetermined regular transmission cycle plus the frame time length of one frame.

4. The tire inflation pressure detection device according to claim 1, wherein:

each of the plurality of transmitters determines whether the tire inflation pressure is restored to a normal state from a decreased state based on the detection signal of the sensor, and transmits, when the tire inflation pressure is restored to the normal state, the frame at the frame transmission time interval less than the regular transmission cycle during the high-frequency transmission zone set to be greater than or equal to the intermittent cycle at a frequency higher than a frequency before a decrease of the tire pressure occurs.

5. The tire inflation pressure detection device according to claim 1, further comprising:

a warning device for a warning on the decrease of the tire inflation pressure upon detection of the decrease of the tire inflation pressure in the receiver,

wherein the receiver stores, upon the detection of the decrease of the tire inflation pressure while the ignition switch is in an off state, a record of the detection of the decrease of the tire inflation pressure, and gives a warning on the decrease of the tire inflation pressure based on the record through the warning device when a driver uses a vehicle.

6. The tire inflation pressure detection device according to claim 4, further comprising:

a warning device for giving a warning on the decrease of the tire inflation pressure upon detection of the decrease of the tire inflation pressure in the receiver,

wherein the receiver stores, upon the detection of the decrease of the tire inflation pressure while the ignition switch is in an off state, a record of the detection of the decrease of the tire inflation pressure, and gives a warning on the decrease of the tire inflation pressure based on the record through the warning device when a driver uses a vehicle, and stops giving the warning on the decrease of the tire inflation pressure by erasing the record when the tire inflation pressure is restored to a normal state from a decreased state while the ignition switch is in an off state.