JP5663756B2 - Tire temperature monitoring device - Google Patents

Description

  The present invention relates to a tire temperature monitoring device, and more specifically, a tire temperature monitoring device that measures the temperature of an inner peripheral surface of a tire mounted on a vehicle with a rim assembled, and can accurately measure the temperature of the tire in a non-contact manner. About.

  When the air pressure of the tire mounted on the vehicle decreases, the tire travels while repeatedly undergoing a large deformation, which may shorten the life of the tire or cause an accident. Moreover, there is a possibility that the performance of the vehicle may be deteriorated such that the braking distance during braking is extended or the cornering characteristics are deteriorated. Therefore, in recent years, a device (Tire Pressure Monitoring System: hereinafter simply referred to as “TPMS”) for monitoring the air pressure of a running tire has been developed for the purpose of managing the tire air pressure.

  In this TPMS, in order to grasp the degree of tire damage caused by a decrease in tire air pressure, the tire temperature is measured together with the tire air pressure. As a method of measuring the temperature of the tire, a method of measuring the air temperature in the tire cavity has been preceded. However, since it has become clear that there is a difference between the air temperature and the temperature of the tire, means for directly measuring the tire temperature have been developed, for example, a measurement method in which a thermocouple or thermistor is embedded in the tire, As in Patent Document 1, an indirect measurement method is proposed in which a flexible magnet is attached to the inner circumferential surface of a tire, and a change in magnetic force due to temperature is detected by a magnetic sensor attached to the wheel to estimate the temperature. ing.

However, in the former measurement method by embedding the sensor, there is a problem that the wiring is cut or the strength of the tire is affected. In the latter indirect measurement method using the flexible magnet, the running tire There is a problem that errors occur due to centrifugal force, vibration, deformation, and a magnetic field outside the tire.
JP 2004-132864 A

  An object of the present invention is to provide a tire temperature monitoring device that can accurately measure the temperature of a tire mounted on a vehicle without contact.

In the tire temperature monitoring device of the present invention that achieves the above-mentioned object, a temperature sensor that detects the temperature of the inner peripheral surface of the tire is installed in the cavity of the rim-assembled tire, and the detection signal of the temperature sensor is transmitted to the tire. In the tire temperature monitoring device configured to wirelessly transmit to a receiving unit installed outside the temperature sensor, the temperature sensor includes a thermopile sensor that outputs an electric signal according to the intensity of the input infrared light, and the thermopile sensor is The infrared incident hole is opposed to the inner peripheral surface of the tire and is attached to the inner peripheral surface of the bead portion of the tire which is a non- variable portion in the tire cavity.

Assemble the thermopile sensor module with the signal processing circuit, the module, it is desirable to mount the inner peripheral surface of the bead portion of the tire, the mounting fixed desirably by an adhesive.

  The infrared incident hole of the thermopile sensor is preferably opposed to the inner peripheral surface of the tread portion of the tire or the inner peripheral surface of the sidewall portion of the tire.

  According to the tire temperature monitoring device of the present invention, the thermopile sensor, which is an infrared sensor, is used as the temperature sensor of the tire temperature monitoring device, and the thermopile sensor is attached to a non-variable portion in the tire cavity, so that it is added to the tire. Since the temperature of the tire inner peripheral surface can be directly measured via infrared rays in a state where the influence of centrifugal force, vibration and deformation is small, the temperature of the tire mounted on the vehicle should be measured accurately without contact. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a reference example of tire temperature monitoring device.

  In FIG. 1, reference numeral 1 denotes a module assembled from a thermopile sensor 2 as illustrated in FIG. 2 and a signal processing circuit 3 as illustrated in FIG. This module 1 is formed on the surface of the well portion 7 of the rim 6, which is a non-variable portion in the hollow portion of the tire 4, with the infrared incident hole 20 of the thermopile sensor 2 facing the inner peripheral surface of the tread portion 5 of the tire 4. It is fixed with an adhesive. The tread portion 5 is one of the most prone to failure in the tire 4, and the thermopile sensor 2 detects the temperature of the tread portion 5 in a non-contact manner. As a means for attaching the module 1, in addition to an adhesive, the module 1 may be fixed by a steel or resin band that is annularly wound around the well portion 7.

  The thermopile sensor 2 is a kind of infrared sensor in which small thermocouples are connected in a plurality of stages. As shown in FIG. 2, infrared rays emitted from an object located within the viewing angle α are taken from the infrared incident hole 20, The light is condensed on the thermopile element 22 by the lens 21 and an electric signal corresponding to the intensity of infrared light is output from the electrode 23.

  The tire 6 is repeatedly deformed to generate heat due to internal friction, and generates infrared rays corresponding to the amount of generated heat. By making the intensity of the infrared rays incident on the thermopile sensor 2, the tire inner surface temperature can be measured. .

  FIG. 3 is an example of a signal processing circuit 3 assembled in the module 1 together with the thermopile sensor 2. The signal processing circuit 3 includes an amplification circuit 30 that amplifies the detection signal of the thermopile sensor 2, a filter circuit 31 that removes noise from the amplified detection signal, and an A / D that converts the detection signal from which noise has been removed to digital. From the D converter 32, the control circuit 33 that processes the digitally converted detection signal, the RF circuit 34 that transmits the detection signal to a receiving unit (not shown) installed outside the tire, and the transmission antenna 35 Mainly composed. The control circuit 33 is composed of a microprocessor and includes a storage circuit 36 for storing data. These electric circuits are driven by a power source 37 (battery) connected to the control circuit 33.

  An example of the operation of the module 1 shown in FIG. 3 will be described with reference to FIGS.

  A detection signal T related to the inner surface temperature of the tread portion 5 of the tire 4 detected by the thermopile sensor 2 is input via the amplifier circuit 30, the filter circuit 31, and the A / D converter 32 (S10), and transmitted to the RF circuit 34. It transmits toward the receiving part installed in the outer side of the tire 4 through the antenna 35 (S11). Next, a predetermined value X stored in advance in the storage circuit 36 is input (S12). As this predetermined value X, the upper limit temperature etc. which can ensure the intensity | strength of the tire 4 are illustrated. Then, the detection signal T is compared with the predetermined value X (S13), and if the detection signal T is larger than the predetermined value X, an alarm is transmitted to the receiving unit (S14). If the detection signal T is equal to or less than the predetermined value X, the detection signal T is input again after a predetermined time has elapsed (S10). Note that the detection signal T and the alarm received by the receiving unit installed outside the tire 4 are transmitted to the driver through visual or audible means.

In the reference example described above, the module 1 incorporating the thermopile sensor 2 is attached to the well portion 7 of the rim 6 which is a non-variable portion, and the tread portion 5 of the tire 4 is monitored. On the other hand, the tire temperature monitoring device of the present invention is illustrated in FIG. 5 as an example of the mounting location of the module 1 and the monitoring location for the tire 4.

As illustrated in FIG. 5, in the present invention , the mounting location of the module 1 is set to the inner peripheral surface of the bead portion 10 of the tire 4, and the thermopile sensor 2 monitors the inner peripheral surface of the sidewall 9. The bead portion 10 is a constituent portion of the tire 4, but is a portion fixed to the flange portion 11 of the rim 6, and thus corresponds to a non-variable portion in the cavity portion of the tire 4 assembled with the rim. When the bead portion 10 is selected as a non-variable portion as an attachment location of the module 1, it is effective in the case of a large tire where the rigidity of the bead portion 10 is very large as in a construction vehicle (OR tire). As a fixing means of the module 1 with respect to the inner peripheral surface of the bead part 10, fixing with an adhesive is preferable.

According to the present invention described above, with use of the thermopile sensor 2 is an infrared sensor capable of measuring without contact the tire temperature monitoring device, a tire cavity such as the inner circumferential surface of the bead portion 10 of the thermopile sensor 2 tire 4 The temperature of the inner peripheral surface of the tire 4 can be directly measured via infrared rays while the influence of centrifugal force, vibration and deformation applied to the tire is reduced. Therefore, the temperature of the tire 4 attached to the vehicle can be accurately measured without contact.

Data is a partial cross-sectional view of a tire showing a reference example of a tire temperature monitoring device. It is a conceptual diagram which shows the structure of a thermopile sensor. It is a block diagram which shows the example of the circuit for signal processing of a thermopile sensor. It is a flowchart which shows an example of operation | movement of a module. 1 is a partial sectional view of a tire showing a tire temperature monitoring device according to an embodiment of the present invention. is there.

Explanation of symbols

1 module 2 thermopile sensor 3 signal processing circuit 4 tire 5 tread portion 6 the rim 7 well section
9 Side wall part 10 Bead part 11 Flange part 20 Incident hole 21 Lens 22 Thermopile element 23 Electrode 30 Amplifier circuit 31 Filter circuit 32 A / D converter 33 Control circuit 34 RF circuit 35 Transmitting antenna 36 Storage circuit 37 Power supply

Claims (6)

A temperature sensor for detecting the temperature of the inner peripheral surface of the tire is installed in the cavity of the tire assembled with the rim, and a detection signal of the temperature sensor is wirelessly transmitted to a receiving unit installed outside the tire Tire temperature monitoring device
The temperature sensor comprises a thermopile sensor that outputs an electrical signal corresponding to the intensity of the input infrared ray, and the thermopile sensor has a non- fluctuation in the tire cavity with its infrared incident hole facing the inner peripheral surface of the tire. A tire temperature monitoring device attached to an inner peripheral surface of a bead portion of a tire as a part . The assembled module thermopile sensor with the signal processing circuit, the module, tire temperature monitoring device according to claim 1 attached to the inner peripheral surface of the bead portion of the front Symbol tire.   The tire temperature monitoring device according to claim 2, wherein the module is fixed to an inner peripheral surface of a bead portion of the tire with an adhesive.   The tire temperature monitoring device according to any one of claims 1 to 3, wherein an infrared incident hole of the thermopile sensor is opposed to an inner peripheral surface of a tread portion of the tire.   The tire temperature monitoring device according to any one of claims 1 to 3, wherein an infrared incident hole of the thermopile sensor is opposed to an inner peripheral surface of a sidewall portion of the tire.   The tire temperature monitoring device according to any one of claims 1 to 5, wherein the tire is a tire for a construction vehicle.

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