JPS6013236A - Tire monitoring sensor - Google Patents

Abstract

PURPOSE:To make it possible to detect the phenomena concerning a tire by a compact, light-weight, inexpensive sensor without a power source, by combining a piezoelectric element and a transmitter, which transmits voltage pulses generated in the piezoelectric element, through an elastic body, and embedding them in the tire. CONSTITUTION:A monitoring sensor 1 comprises a piezoelectric element 3 or a combined body of the element and a mass body 5, which amplifies the deformation of the element; and a transmitter 6, which transmits voltages pulses generated by the piezoelectric element 3. Both parts are electrically connected through an elastic body 7. The sensor is embedded in the outer surface of tire 8, with the tip of the mass body 5 directed outward. At the time of the normal rotation, output pulses 9 with a constant interval are converted into an electromagnetic wave by the transmitter 6 and displayed on a display device in a vehicle, when the rotation of the tire is started. When the pressure in the tire is decreased, peculiar pulses 10 are displayed. When the abrasion of the tire reaches the limit, extremely high pulses 11 are displayed. Thus, the phenomena of the tire can be detected by the compact sensor at low costs without power source.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a tire monitoring sensor for monitoring the driving conditions and abnormalities of tires for vehicles such as automobiles.

(b) Prior Art and Problems Tires of a running vehicle are exposed to various conditions depending on road surface conditions, and constantly monitoring the condition of the tires is extremely important for driving safety. Conventional tire detection and warning devices include wear warnings based on the depth of the grooves in the tread pattern, and internal pressure display devices set in the air inlet, but these are all mechanical means, so this warning cannot be used. There were limits to the ability to notify drivers. Phenomena that should be warned about tires include wear, burst,
There are problems such as locking, rolling tires, etc., and there is a demand for detecting these various abnormalities and ventilating the vehicle interior with a warning by display or voice.

However, it is necessary to install separate sensors for each function such as temperature, pressure, rotation, contact, etc., and a power source is required to drive these, and it is also necessary to monitor the wear and tear of these sensors. There is a method using a telemeter, but it is generally difficult to use because it is susceptible to noise and is expensive.

Purpose of the Invention In order to solve these problems, the present invention detects abnormalities in tire-related phenomena in a compact, lightweight, and inexpensive manner without power supply, and transmits them to the vehicle body without contacting the rotating tires. The present invention provides a tire monitoring sensor that can send a signal to a central alarm system.

B) DISCLOSURE OF THE INVENTION An example of a main body of a monitoring sensor according to the present invention is shown in FIG. This sensor 1 is embedded inside the outer peripheral rubber of a vehicle tire 8. The monitoring sensor main body includes a transmitter 6 for converting a polarized glass made of lead zirconate titanate porcelain or the like into electromagnetic wave transmission, and both are electrically coupled via an elastic body 7. In FIG. 1, a mass body 5 is provided in contact with the piezoelectric element 6 and is set in the storage case 2. This mass body amplifies the pressure transmitted to the tire and increases the voltage generated by the piezoelectric element. Effective when necessary.

In addition, if this mass body is made of highly wear-resistant cemented carbide and its tip shape increases the contact resistance with the road surface, it can have the function of a snow spike by embedding the tip of the mass body in a protruding manner on the outer peripheral surface of the tire 8. You can also do it. Further, the embedding point in the tire may be either the center part or the innermost part of the tire outer circumferential rubber. The piezoelectric element does not generate any voltage when it is stopped, but when the vehicle is running and the tires begin to rotate, they generate voltage pulses depending on the rotation speed and the contact status with the road surface.
This voltage pulse is converted into electromagnetic waves transmitted to the vehicle body by a transmitter connected via a lead wire, and the tire condition can be displayed on a display device inside the vehicle.

Next, an example will be explained.

FIG. 6 shows the output pulses of the piezoelectric element indicating various conditions of the tire. FIG. 6(a) shows the case of normal rotation, and the output pulses 9 are generated at regular intervals l. Depending on this interval l, rotational speed, slippage, and lock alarms can be issued. When the tire pressure decreases and the tire burst occurs, the shape of the tire after contact with the ground is abnormally deformed, and accordingly, the pulse from the piezoelectric element produces a unique pulse of 1° as shown in FIG. 6(b). These pulses can be easily identified because they occur at extremely short intervals compared to vehicle speed pulses.

Next, when the monitoring sensor shown in FIG. 1 of the present invention is embedded with a mass body positioned inside the tire at the wear limit as shown in FIG. As the surface wear progresses and the tip of the mass body gets closer to the surface, the voltage pulse generated in the piezoelectric element increases significantly, as shown in FIG. 6(c).Tire wear can be detected by the received electromagnetic waves.

As explained above, since the monitoring sensor of the present invention uses a piezoelectric element, it does not require a power source, and can detect various abnormality information necessary for tires with one sensor. When incorporated into a storage system, it is extremely inexpensive and easy to install.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the monitoring sensor of the present invention, Fig. 2 is a cross-sectional view of the sensor embedded in a tire, and Fig. 6 is an example of output pulses of a piezoelectric element indicating the condition of the tire. It is. 1: Monitoring sensor, 2: Case, 6: Piezoelectric element. 4 elite wire, 5: mass body, 6: transmitter, 7: elastic body,
8: Tire, 9, 10, 11: Output pulse 1st haze 2nd figure 30

Claims (1)

[Scope of Claims] (1) A piezoelectric element alone or a composite body with a mass body for increasing the deformation of the piezoelectric element 1] and a transmitter for transmitting voltage pulses generated in the piezoelectric element are arranged on an elastic body. What is claimed is: 1. A tire monitoring sensor, characterized in that the sensor is embedded in a tire for a wheel; (2) A tire monitoring sensor according to claim 1, characterized in that the tip of the mass body coupled to the piezoelectric element is embedded in a protruding state on the tire surface. (6) Patent The tire monitoring sensor according to claim (1), wherein the monitoring sensor is completely embedded inside the tire.