JPH11321256A - Tire pneumatic alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the formation of a floating capacitor by covering a high frequency part generating the radio wave of an electronic board with a protecting case to isolate if from a resin molding material in the clearance of the case. SOLUTION: This device is provided with a high frequency part for generating radio waves within a case 1 fixed to a tire wheel. With respect to an electronic board 3 fixed by a protruding part and screw 5 provided on the bottom of the case 1 and a power source battery 2 having terminals 2a, 2b fixed to the electronic board 3, the clearance between them in covered with a resin molding material 6. Further, a protecting case 7 is provided for separating the high frequency part of the electronic board 3 from the molding material 6 is provided. Since the formation of a floating capacitor in the high frequency part can be protected by providing the protecting case 7 to isolate it from the molding material 6, an uncertain influence is eliminated, and the operation at high temperature can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire pressure alarm device which detects abnormal tire pressure of a vehicle and notifies the driver of the abnormality.

[0002]

FIG. 3 shows a conventional resin mold transmitter. The conventional resin mold transmitter includes an oscillator 8 for outputting a fundamental wave, a capacitor 9 for multiplying the fundamental wave, and a coil 10.
A transmitter comprising an LC parallel resonance section 11 consisting of: and an antenna 12, and covering these with a resin molding material 13. A silicone resin is used as the molding material 13, and the molding is performed by molding. assuming the capacitance C ₁ of the floating capacitor 14 formed in parallel with the LC parallel resonance unit 11, the capacitance C ₂ of the capacitor 9 of the LC parallel resonance unit 11, the floating capacitor from the capacitance C ₀ of the original computational needs value C obtained by subtracting the capacitance _{C 1} of 14
In the ₀ -C _1, it had lost the influence of the stray capacitor generated by coating the resin molding material.

[0003]

However, when used as a transmitter of a tire pressure warning device mounted on a tire wheel, operation at high temperatures is required. At high temperatures, the characteristics of each electronic component change, and not only the floating capacitor formed in parallel with the LC parallel resonance part as in this resin mold transmitter, but also between the configured electronic components and the pattern of the electronic board. Etc., it is easily affected by the capacitance of the floating capacitor formed. In particular, the high-frequency part that generates radio waves is easily affected by the capacitance of the floating capacitor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a protective case 7 is provided on a high-frequency portion of an electronic substrate which is easily affected by capacitance. It is intended to isolate the floating capacitor from the floating capacitor.

That is, the tire pressure alarm device of the present invention is a device for detecting an abnormality in the tire pressure and transmitting the information to the vehicle side by using radio waves to issue an alarm. In a transmitter covered with a material, an electronic substrate 3 and a power supply battery 2 having terminals 2a and 2b fixed to the electronic substrate 3 are arranged inside a case 1 fixed to a tire wheel, and Electronic substrate 3
The high-frequency portion that generates the electric wave is covered with a protective case 7, the gap of the case 1 is covered with a resin molding material 6, and the molding material 6 and the high-frequency portion of the electronic substrate 3 are separated by the protective case 7. A resin-molded transmitter.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a structural diagram of a tire pressure alarm device of the present invention. The tire pressure alarm device of the present invention includes a high-frequency unit that generates radio waves inside a case 1 fixed to a tire wheel, and is fixed with a convex portion 4 provided on a bottom surface of the case 1 and a screw 5. Electronic substrate 3
And a power supply battery 2 having terminals 2 a and 2 b fixed to the electronic substrate 3, and a gap therebetween is covered with a resin molding material 6. A protective case 7 for separating the parts is provided as shown in FIG.

[0007]

As described above, the tire pressure alarm device according to the present invention provides a protective case for a high-frequency portion which is particularly susceptible to the influence of the capacitance of the floating capacitor formed in each portion by the coating of the resin molding material 6. 7
Is provided, and is isolated from the molding material 6, and the formation of the floating capacitor in the high frequency part is eliminated, so that the uncertain influence is eliminated and the operation at a high temperature can be realized. Transmitters mounted on tire wheels must be covered with a resin mold material because vibration, centrifugal force, etc., are applied to the internal electronic components.Because they are exposed to high temperatures, they can operate at high temperatures. Because of the demands, the present invention was able to provide a transmitter that operates even at high temperatures using a mold material.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a tire pressure alarm device of the present invention.

FIG. 2 is a perspective view of an electronic board provided with a protective case of the present invention.

FIG. 3 is a block diagram of a conventional resin mold transmitter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Case 2 Battery 3 Electronic board 4 Convex part 5 Screw 6 Mold material 7 Protective case 8 Oscillator 9 Capacitor 10 Coil 11 LC parallel resonance circuit 12 Antenna 13 Mold material 14 Floating capacitor

Claims (1)

[Claims] An apparatus for detecting an abnormality in tire air pressure and transmitting the information to a vehicle using radio waves to warn the vehicle. Particularly, in a transmitter in which internal electronic components are covered with a resin molding material, An electronic substrate 3 and a power source battery 2 having terminals 2a and 2b fixed to the electronic substrate 3 are arranged inside a case 1 fixed to a tire wheel, and a high-frequency wave for generating a radio wave of the electronic substrate 3 is provided. A resin mold transmitter in which a cover is covered with a protective case 7, a gap of the case 1 is covered with a resin mold material 6, and the mold material 6 and a high-frequency portion of the electronic board 3 are separated by the protective case 7. A tire pressure warning device, comprising: